Research online and see what you're interested in doing and what you'd be able to spend. There's a great site called: "Yes, they're fake" which reviews procedures, products and has feedback from members. I have a small line in my middle lip that I'm going to get some filler in. Maybe Restalyne. If you have a lot of lines, you can get a chemical peel done in that area. Depending on how deep they are will determine what kind of peel you should get.
I got a light peel a few years ago just to even out my skin tone and for light lines. It was great. But you absolutely have to stay out of the sun and give up smoking. I never smoked though.
OTC products can only do so much. Retin-A products (They are prescription) can minimize, but again it depends how deep your lines are. I use Renova and a Vitamin C that I got from my PS.
Anyway research and see a reputable professional. Let us know what you do!