Be yourself.
Any relationship on not being yourself is going to **** up very quickly when he/she eventually realises.
On first dates, a sense of humour is a big plus. Props if you can throw a joke or two back at me. Sarcastic humour is cute.
Don't go overboard on looking good, because it shows.
Show interest in what I'm talking about even if you aren't really that interested and I'll do the same for you, it keeps the conversation flowing - don't forego telling me about your dayjob because you think it's boring.
If you consider yourself a feminist, don't announce it. Equally, don't be misogynist/misandrist.
If you're religious, don't be, uh, religious about it.
Don't be overly conventional. If you're all about going to fancy bars or restaurants on a date, you're dating the wrong guy. Suggesting meeting up randomly in a city centre is just fine.
That's all I got.