The lines at the end of your smile are natural and you are supposed to be there. If there are lines left when you smile it is because you are wearing way too much foundation and possibly the wrong color. or it has bad coverage. If it has bad coverage you may be putting a bunch on to make up for the fact that it either is not the right color or the coverage is bad. I would suggest a dept store brand like Clinique where they professionally match it to your skin, and it has excellent coverage.
Plus, by caking on so much foundation you are really hurting your skin by clogging to pores, therefore bringing on more acne, and then you just pile on more foundaiton to make up for it. So I would try and use less, plus you will go through your makeup a lot slower.
Use foundation only on blemish areas or red areas, and use mineral powder on the rest of your face. It will still give you coverage but won't make it look like your wearing a lot of make-up. If your concerned mineral powder won't give you enough coverage don't worry. I have rosacia and if I put a tiny tab of liquid foundation or concealer on those areas and cover with mineral make-up, they disappear! The condition of your skin will also improve over time.
the 2 best mineral powders I've used and would recommend are
1. MAC 's. You can get at at Belk or Macy's I'm pretty sure. This gives more coverage
2. Clinque Smart Mineral Make-up is what I'm currently using. It has a grinder on it so you don't have to worry about he powder spilling all over the place.
Bare Minerals will probably not be enough coverage for you,
use bare minerals if you've ever seen the infomercial on it. it really does work! lol I've used it for 4 years. I was always the type who couldn't walk out of the house unless I had cover up on, but I just recently ran out of it about a year ago, and have never wore a speck of cover up since. seriously you should try it, a bit expensive, but you will end up spending more money on something cakey that lasts you less time compared to bare minerals that will last you years and actually works.
try using a make up primer.. they normally help keep the make up on a bit longer and better. hope that helps!