Whenever I have a manicure it lasts about a week, even when I take in my own polish for them to apply (so I can touch up if nec). When I do it (using a decent base an dtop coat, applying 2 - 3 coats of colour in between) it chips the next day. Any suggestions as to what I'm doing wrong? Should I apply the polish thickly or thinly? Is there some trick with the brush strokes? I've tried loads of different brands, top base costs etc and now some spray that's supposed to make it last but all to no avail :(