Remember when dating that many tend to leave their guard down which is unwise. Meeting for drinks, never accept a glass of something that you did not see being opened or go to the restroom leaving your drink there on the table. There are people who might lace your drink with some form of date rape drug. Tell a friend your plans and when you are expected home with a check in. If possible, and when appropriate take a picture of their car's tags and email to a friend so that if something bad happens this can be given to police. Never invite them back to your place until you are comfortable which for me might be three or four dates and then ahead of time will make sure valuables are hidden. In regards to transgender, as Monica indicated to disclose this until they have acknowledge this fact. I have needed to do this a handful of times, not with online dating but when out with friends where it happens somewhat like they come over to your table and interjecting into your conversation, ask to buy you a drink etc. Be careful how you tell them you are trans as it can offend their manhood especially if they are intoxicated.