Before going all the way, be sure to get clear consent and discuss safe sex options. Bring up sex in a comfortable, relaxed environment.
Help them feel safe and comfortable, and try to read their body language to ensure they feel at ease. You might be on a date at a restaurant or other public place when you bring up having sex.
Be mindful of those around you. Be honest about how your potential partner makes you feel.
Let them know you find them attractive, but make sure any compliments you offer are sincere. Don't go into a vivid description of what you want to do with them. If they aren't ready for sex, this could put them off.
Try to keep the conversation light-hearted. Let me start over. However, self-deprecating humor can kill the mood, so go easy on making fun of yourself. Do you want to take this further? We can stop if this is going too fast.
Joke around about pleasing them to break the ice. Let them know you want to make the experience as enjoyable as possible. Asking someone what they enjoy sexually or what they fantasize about puts them in a vulnerable position.
Try telling them how you like to be touched or a position that you enjoy.
You can say "I like kisses on my neck," but don't say "Man, it really turned me on when my last girlfriend kissed my neck and gave me hickies. However, the experience will be more fun and less awkward if you know that a spot is extra sensitive or a position is uncomfortable for your partner. Be attentive to their body language, and try to stay in the moment instead of overthinking things.