The diet should be balanced and match the animal's age and activity. Change foods gradually over 5–7 days to avoid upset.
Patience beats pressure. Reward the behaviour you want and avoid punishment, which erodes trust.
Do not overlook emotional needs: attention, play and a predictable schedule reduce stress and build trust.
Watch behaviour closely: changes in appetite, activity or mood are often the first sign of trouble. Keep a simple journal.
Not entirely sure, our experience differs, but good article.