Hi there,
practice and more practice is the prefect tool... I know, its hard, it gets frustrating, but anything that is worth doing is worth investing time on.
there is a fab tutorial on here that The Geek did, it helped me getting my smile lines to smile......
http://www.salongeek.com/nail-application/2734-million-dollar-smiles.html
You can follow it step by step..... give it a try....I am right handed so my dominant side is the right, I would always start there, Liza Smith gave me this fab tip, after placing your bead, start at the non dominant side first, it made so much difference.....
Practice, practice and practice some more, I went through a box of 500 tips to get it right lol....and eventually it clicked....
Dont give up, it will come in time xxxx