The Desperates

Don't try too hard. If you fail once, you fall hard.

So you made a mistake and you're now flustered while trying to get their attention. Don't make another move until after you forget about it. If your mistake you made while trying to flirt with them is constantly on your mind, you'll do even more stupid things. Let it pass, do something else, and ignore teasing like it's nothing.

Most of all, be yourself. If they don't like you for you, sucks for them.