Hi - if you do a quick search in the bit above for minx application, it should come up with some posts about applying minx etc. The minx should be smooth anyway when you apply it to the nails, if you are getting air bubbles or wrinkles you need to follow the advice on the threads - sorry its late and im about to go to bed so brain isn't working lol.
some people use a top coat like lumos (great top coat by the way) on the free edge to help seal in the minx. But to be honest Ive never used any other product and the minx have lasted fine both on fingers and toe nails.
It may be a case of just get your mates in and practice, practice and practice some more to get the smoothness - but you will soon pick it up :wink2: