Go to a bar with a solid reputation for being a cougar hangout. Dance, have some fun, enjoy a few drinks - be seen to be having fun. For that, it is better to have a wingman around. Just ask any lady to dance. If you're nervous about it, simply ask one of the many ladies who will be dancing with their girlfriends, or with a variety of guys, or by themselves. Don't look like a player at this point, simply ask them for an innocent dance. The ladies you dance with and joke with through the evening, though, are not necessarily the ones you want to target to take home. It might work out, and if so great, but the point for your first few hours is to be seen by the hard-core cougars who are watching you have a good time.
If you're still on the prowl towards the end of the evening, zero in on the drunk-ish ones who are hanging around to the bitter end. When given a choice between going home with the balding 50-something Larry or going home with you, the younger buck who's been dancing and having a good time all night, you will win. And you will bag your cougar. Good luck.