I tried a couple of holsters and have a couple more on the way. I carry a Kahr CM9.
First, just a cheap "Uncle Mike's" holster, which certainly does the job but you do have to press it against your leg to get the holster to stay behind. It allows a good grip of the gun before you pull it out, however. I had a little bit of a problem with printing.
Second, I found a guy who sells on Ebay, they're called "Trace Tarco" holsters. Leather, very inexpensive ($18) and seem to work well. The benefit is that it has a wallet-like covering on one side so there is absolutely no printing even in the tightest and thinnest of pants. However, it also has a vertical split in this flat side so you can get your fingers in easily. This stays in the pocket on the draw and is very nice. This is probably the best for printing.
Third, Alabama holsters makes thinner Kydex holsters with a bit of a hook on the end to aid in retention. These are thin and don't print much. Thumb tab to push and get your gun out, which is nice. Around $25.
Fourth is Desantis Nemesis holster. Sticky and helps in retention, doesn't print too bad. Nothing really superior over the others though.
I really like the Trace Tarco and the Kydex one. The others are so-so in my opinion but then again, I typically wear slacks or cargo shorts.
This video might be helpful to you: