1- Drop your luggage at the door. So so many times we see people bringing in baggage from Facebook, baggage from Twitter. Baggage from other roleplaying groups and relationships. This is a new start. What happened elsewhere has no bearing on what happens here. Use this chance to be the best version of yourself you can be.... don't pollute the new well with the old poisons and prejudices.
2- WRITE. So many want people to write with right away. The thing is, people want to see your character, to see if they'd be able to mesh well. To see if they enjoy your style of writing. To see if the story is entertaining or captivating. Your profile is a combination resume, job application, and help wanted flyer. You need to advertise yourself, your story, and what you are looking for without actually shouting "I'M LONELY AND NEEDY TALK TO ME" because, well, that makes people run away. Add some writing. Do a few blog posts and be sure to set the privacy to "everyone can see". Draw people in. If the profile is nothing but "like for a starter", "rp anyone", "I'm so bored nothing ever happens here".... people looking will assume that you cannot write on your own, or come up with any ideas, and so they'd be the ones doing the bulk of the work. This is why some have issues finding writing partners. You aren't selling yourself well, you're selling yourself short.
3- Stay out of drama. If you or a friend is having an issue, there is a private messaging system set up for talking privately. Your entire friends list does not need to be drawn into the private he said/she said, so and so is a slut, so and so broke my heart drama. All it proceeds to do is to cause your friends and their friends to have issues, and create more drama. Handle that stuff privately like adults. Don't emotionally manipulate your friends. If you want to leave, you'd leave. Posting that you're going to leave just so your friends pay attention to you is wrong. Same with the "cleaning my friends list". It's a cry for attention and it looks bad. You can clean a list without broadcasting it, like your list is so exclusive that people who aren't on it only wish they were. If you want to leave? Do it. If you want to clean your friends list, its yours, clean it. You don't need to make other people feel like crap with any of this stuff. It's emotional manipulation of those that you are supposed to respect and care for.
4- Remember this is NOT Facebook/Twitter/Tumblr. People go to those sites to see daily updates, funny memes, music posts, and random ramblings. RPL is a writing site, people come here to write and to read writing. Too many OOC posts, real life spazzing, meme/photo posts, song links, or random "prompt" posts will flood their feeds and turn people off. You will lose friends for this, as most people don't want a feed filled with junk instead of writing content. If you want to post those things, having a Facebook account and an RPL account might help you separate the two a little bit better. You can always link to other accounts in your "Info" section for people that want to see every thought you post.
5- Spread yourself out. There are some great groups and great people here. Will every person you meet be awesome? Of course not. There are always going to be people we don't get along with, stories or posts we don't like. There are always going to be people that you like but don't like you back. This is just a giant high school, really. Cliques and all. BUT just like in high school, there are people who manage to flit in between every type of group, every type of personality, and bridge the gaps. If you meet someone you don't mesh with? Walk away gracefully and on to the next. You'll find those that are a great fit for you, but the "gracefully" part is important. People talk, reputations spread. You will find that people know "of" you before they meet you officially. See point 3 and the friends list part. Make your writing a star, not your involvement in someone else's games.
6- Remember that this isn't real life. Yes, we become close to our writing partners. Yes, sometimes those relationships turn real. However, one important thing to remember is that sometimes we all have different faces. My writing partners on one face have zero bearing on what my other face is doing. Roleplaying is like separating your brain into an apartment complex. Someone on the first floor can't go upstairs and wander into a stranger's room just because they have the same poster on their door. Unless your writing partner wants to share with you, you do not need to know their other faces or other writing partners. Try as we might to say we're better than that, it can and does cause jealousy, even for those of us that are as well adjusted as we can be. Just keep yourself out of that level of quicksand. Out of sight, out of mind. It's far too easy to take everything as a personal slight when it shouldn't be. Easier to just not look for "clues" and hidden issues in the first place, because likely they weren't there anyways. Someone else's characters are none of your business. You can write with the person in apartment C without having to learn a single thing about the occupants of apartments A, B, and D. It also has no bearing to you how many people visit those other apartments, or whether there's a party going on or not. You aren't invited, you were asked to have a quiet night in with your friend from apartment C. Enjoy it and stop worrying about the rest of the place.
7- READ. Just like with number 2 up there. People are writing so that they can share their story and hopefully find other people to write with. Reading serves as an inspiration. A lot of times if serves to help bring new ideas, see different aspects of roleplaying that you may not have thought of before. It helps show you what others are writing, so you can make your ideas maybe more unique. It helps people get better by seeing all the amazing different avenues and ways that people can take to roleplay. Click "like" sometimes. Let the writers you admire see that someone is reading their work. While a lot don't write for that, the acknowledgement can be nice occasionally. If you have someone you really enjoy, drop them an email and let them know. One, it's great to hear, and 2, it can forge a friendship. I did, 2 years ago, and I found the most perfect writing partner for me, who blossomed into a best friend behind the scenes. Don't discard someone just because they have a partner on that face and you need a relationship right the hell now. Find a friend to talk to first. Find writing you enjoy reading. Things can grow if you're patient enough, and those end up being the strongest writing relationships anyways. My writing partner had another partner as well, and we ended up creating new characters for each other to try writing together too. People can be more than one thing to one person. And if not? Then you still have a good friend because you gave someone a chance to get to know you.
8- Remember, roleplaying is in essence writing someone else's daily life. Every life can't be rainy all the time, unless you're roleplaying Eeyore. You aren't expected to be chronically happy, or full of more drama than a Mexican soap opera. In every life there will be days where sometimes people just want to read a quiet night in for your character. Having a roleplay that is constantly fraught with danger and intrigue and drama is fun, yes...... the first 5-10 times you read it. After that it gets tiring. Same with the pathological happiness. Throw some good days, some bad days, some boring days, and just.... some realism to your roleplays. If your character can make others empathize with them, that's half the battle won.
9- Respect the relationship! If someone is taken, don't be an ass. Respect their writing partner. This shouldn't need to be said, but clearly it has to. Don't send smutty messages, tag them in racy pictures, harass them for more than friendship. Don't send kissing and humping and shit in the interactions inbox. It's rude, and it's a quick way to piss people off and lose friends. Respect is earned here, not given freely. If you make a nuisance of yourself, you will quickly find yourself without many friends to interact with. This is the same with jumping into roleplays. If it isn't listed as "open", contact the person first to find out if they'd be okay with you jumping in. If they say no, respect it.
10- The most important one. Every experience is a chance to grow. Don't take criticism personally, listen and really try to see what the other person may have been picking up on before discarding the advice. Lose a friend due to drama? Then you know where not to tread and what situations should throw up warning signs. Have a roleplay unfinished? Try to see what caused it to lose steam so you know next time to maybe add in a slight twist if things start heading that same direction. Find someone who says they don't want to write with you? Ask why, in a nonjudgmental way, and respect their answer. Maybe your writing doesn't mesh, or there are too many typos or grammar errors and its hard for them to understand. Maybe they don't care for the character or the story. Either way, you can find something you can work on for the future, or thank the person for being honest that the characters didn't fit well for them, and move on to the next. Everything is a learning experience, if we treat it as such. Does everyone else have to effect you, and make you change? Nope. Not at all. But at least then you'll know WHY some don't fit well, and accept that instead of being angry about it. There is always a positive in every situation if you look for it. And hey, occasionally the positive may be that you narrowly missed stepping in a bucket of crazy. That's okay too.