I've talked about being a supertaster before, but being a picky eater, in general, is different. You just don't like it. The texture could be fine, the taste is just disgusting.
1. New places
You dread going to a new restaurant, because you can't be sure if they have anything you'll eat. You've taken to looking over the menu beforehand to save yourself any grimaces, and if there isn't anything, you may or may not load up on snacks.
2. Hold the...
Maybe that doesn't always work, and you're forced to order SOMETHING to appear polite. "Yes, I'll have the chicken breast, but hold the mushrooms, asparagus, tomatoes, weird wine sauce, etc." And everyone will judge, whether it be your companions, the wait staff, and presumably the chef. And if it comes with an offending ingredient anyway, no, you can't "just scrape it off."
3. Go-to dish
At places you know, there's that one safe dish you always order. It may be your favorite or the only thing there you can eat. You may get the usual gripes of "You're getting that AGAIN? Why not try something else?" but that's YOUR dish. Even if it's the ever-popular and safe chicken tender appetizer, it's YOUR DISH.
In a bunch of local cultures and households, refusing food is a sign of rudeness. Even if it's a food you hate. Like deviled eggs. Or nuts. Or *shudders* pepperoni pizza. It's fine to not want food if you don't like it, or there's something in it you can't stand, but unfortunately, some people take it as an insult, and you have to find ways around it.
5. "What do you not eat?"
*Ahem* Tomatoes, celery, onions (But they're okay if they're powder or salt), mushrooms, peanut butter, carrots if they're in soup, nuts, eggs (But if they're in something, like cake, it's okay), 99.9% of fruit, black licorice, chunky salsa, all seafood, tofu, any kind of olive unless it's black, tea, black coffee... Yeah, it would be better to ask what I DO eat.
6. "WHAT?! How can you not like *insert offending food here*??!!"
Simple. It's gross. You can't stand it. You tell your friends and family this over and over, even going into detail about how the taste of it makes you gag, but they won't listen. They understand your hatred of said food as much as you understand why people eat it. (I'm looking at you, peanut butter...)
7. No trust, ever
Your friend or relative was nice enough to make you something without an offending food, or you order something on the menu with a "special" request. They may say that there's no *whatever* in it, but you have to check, especially if other people are being served the same with it. You don't mean to be rude, but you can't risk being poisoned.
8. "It's Just a Phase"
People usually think of the little kid who doesn't like veggies when they hear "picky eater," so obviously grown-ups eat everything. Nope. Not true. I hated onions when I was a kid. Now I'm twenty and I still hate them. Some things are just gross. Some things have a weird feeling, and some things just won't agree with you. It's just how your taste buds and your brain works.
Oh well, pass the chicken strips.