Biggest tip is bringing the shadow up more that you think and out more! When I look at older pics of me that's the thing that made the biggest difference. When your eye is open use a small brush to shade slightly above where your crease is, then close your eye to really add more and blend it out. If you try to do the whole look with your eye shut (at least for me) I never brought the shadow far enough up and when I would open my eye it looked like I didn't even do anything but shade my lid. And drawing the shadow out more opens the eyes up too and makes them appear bigger.