Well, you can start with a nice bottle of red wine... LOL
JUST KIDDING!
Make sure your male and female geckos are in 100% good health and you have a good setup that will accommodate them both. Once you know they are ready to start courting, then you should be OK to introduce them to each other. I would probably put the male in with the female in case the male is more territorial...
Either way works. But leo matings can be rough, lots of biting and tail-whipping. Thats partly why I try to set up my male with the chosen females before breeding season, and keep them in a harem. It prevents that 'invader in my territory' reaction. But usually they will get right down to business as soon as they meet.