• Enclosure of the proper size and orientation. Vertical height for arboreals (tree-dwelling) as well as width and depth to enable proper thermoregulation.
  
  
• Sufficient humidity
  
  
• Water offered in a manner that can be utilized by the reptile
  
  
• Suitable & safe substrate (depth & type)
  
  
• Furnishings (logs, sticks, foliage)
  
  
• Proper heating & thermal gradients
  
  
• Proper lighting (day/night cycles , UVA/UVB light)
  
  
• Healthy food, of the size appropriate for the individual
  
  
• Proper cleaning and disinfecting of enclosure, substrate & furnishings
  
  
• Regular monitoring of enclosure & equipment to ensure proper maintenance
  
  
• Regular monitoring of reptiles to detect early signs of stress or ill health.
  
  
• Access as needed to an experienced reptile veterinarian for initial examination of new reptiles & exams & treatment as needed as problems arise.

1997 Melissa Kaplan from "Reptiles: A teacher's Guide to their care and keeping in the classroom"