Dont get your hands wet for 2 hours.
Lifting usually means poor prep (oily nail or too much/little glue). Remove, re-clean, buff lightly, and reapply.
Bubbling means air got trapped. Remove and reapply.
Short-lived wear: try a nail dehydrator/primer (or alcohol wipe + very light buff) and ensure full contact at sidewalls.
Make a bigger press-on fit: gently file the inner sides of the press-on (or the nail sides) to narrow it; you can also slightly curve the edges with a fine file for a snug fit.
For sensitive skin: do a small patch test with glue on skin behind the ear or inner wrist to check for irritation before full use.