Well, you're off to a great start compared to where I was when I started! The exciting thing is that with the right practice, patience and guidance, your work will only get better. So save this pic as a "benchmark" for what you do next!
There are 3 things to focus on that will greatly help:
Design.
The apex (the thickest point) is too far toward the free edge and is too much of a point. The apex should be gradual and 50% of the way between the free edge line and the cuticle line. Take a Sharpie (marker) and put a point there, then put another half way between that point and the cuticle line and another between the half way point and the free edge line (effectively splitting the nail into thirds). Those 3 dots form your apex area (Zone 2).
Smile lines
Smile line is really just down to product control which comes with confidence and the right amount of practice. Here is a tutorial I did about 150 years ago that may help:
http://www.salongeek.com/threads/million-dollar-smiles.2734/
Product control and finishing
When you lack full control of your product (which again, comes from confidence and practice) you create a lot more work with finishing. More work finishing weakens your enhancement which creates more work when rebalancing and maintaining the nail. This is why you want to "Sculpt with your brush and not with your file". Here is a great (classic) tutorial
on product control and
one for finishing.
Finally,
@izzidoll offers her usual sage advice and agree 100% with her!
Hope this helps. Best of luck!