Applying crystals

Hi, I have read numerous threads on here over time and tried almost every method, but I'm still having crystals coming off after a few days.

I have tried gluing them onto buffed nails, which is a pretty good method but most of my customers have gel polish over there full sets so they don't bond onto them very well as they have a shine. Iv tried setting them into gel topcoat (don't hold very long), top coating over them ( takes the shine away), going in between with a striping brush (don't...

Applying crystals