When selecting your sizes, always size down! The biggest culprit to nails prematurely lifting is selecting a size too large for your nail bed. Always lift the strip from the free-edge side (indicated by the ▼ above each strip), as minimizing contact with the adhesive will ensure optimal adhesion.
Also, be sure to apply the anti-stick sealant to avoid dust, hair, and anything else from sticking underneath your nail tips.
Lastly and MOST IMPORTANTLY, always store remaining strips in their container with the cover on. Exposing the strips to any light source can compromise future wear by hardening them prior to the next use.