Dehydration is the most common issue seen in leaf-tailed geckos. Check the fluctuation of humidity levels over the course of the day, check for droplet accumulation on surfaces like walls and leaves, and mist more frequently. If you have a busy schedule, consider investing in an automatic misting system. Installing a magnetic wall-mounted water dish is also helpful.
In cases of a severely dehydrated leaf-tailed gecko, take it to an experienced reptile vet. They will be able to administer saline and provide further advice for recovery.