Nice tips Jac, I have a few myself.
Make sure you take your own drink, a bottle of softdrink for example, and until you get to know the person well enough, politely refuse any they may offer by saying "No, I'm good, I've got my *insert drink name here*".
If you're going to someone's house, tell them you're going to be somewhere that is public and ask if they'd like to meet you there, then get some lunch. This will give you a chance to check them out and see if they're trustworthy. If they seem too eager to head off, make sure you have an excuse to leave.
Don't get into a car with someone unless you trust them.
Check out their posts before you meet them to get an idea of their personality. Then when you're talking to them, quote some of the things they've said to guage if it's actually them, or if someone has highjacked their account to try and lure someone.