1. Don't cosplay to impress someone - Especially if they're strangers, you don't know them, and they're not your friends. Chances are, none of them would care, and you'll only be disappointed and miserable. If you're going to cosplay, do it for yourself. (or perhaps, maybe even for the people who genuinely care, love, respect, and support you).
2. Don't cosplay to spite someone - It takes the fun, enjoyment, and meaning out of the hobby. If you successfully spite someone, you are just making them hate you. Unless you're Kirei Kotomine and people's anguish and hatred sustain you, then stop doing this. (But seriously, Kirei jokes aside, just don't. :p)
|Even Kirei is judging you.|
3. Don't cosplay to make someone jealous - You are corrupting the hobby and inducing hate. Chances are, the person you're targeting doesn't even care, or if they do, it will just encourage more hatred and fights. So, please stop that. It's probably asking too much to want everyone to get along, but I believe small efforts to be a better and nicer person can make a big difference and may start a positive chain reaction.
4. Don't cosplay to become popular or famous - It's a hobby. Do it to have fun and because you love it and it helps you grow or improve as a person. Fame and popularity are just a bonus.
5. Don't cosplay a character just because you think you're better at it than anyone else who already cosplayed it and those who are planning to cosplay it - Seriously, you are not the character. You are just portraying it through cosplay. Good for you if strangers and friends praise or acknowledge your cosplay, portrayal, and your craft. If not, don't let it get to you. Either way, don't let it get to your head.
I've been cosplaying for years now and I know I have gone through some of these feelings before, but I realized that all they have done to me is make me feel bad about myself and treat people badly. They add to the drama, too. But I believe it is never too late to change oneself if you are willing to become a better person. If you are guilty of one or all of these things, I hope I have somehow opened your eyes to the reality. Now, I am encouraging you to become a better and happier person. ^_^'