Storage: Keep your Djembe inside with you to maintain a steady temperature & humidity which will avoid damage to the skin, which will stretch when humid & contract when dry.
Tightening: Avoid initial over-tightening - tighten a little then play & repeat - this will allow the skin to gently settle in.
Should you oil the drum head? No, as this will keep the drum sounding "wet"
Protect the drum shell: oil the shell regularly & keep away from pets & sharp metal objects. Linseed oil, Palm oil & Coconut oil are all suitable
Always play with clean hands
Small line cracks along the top and bottom of your drum are normal
Be careful when transporting your drum - ideally use a padded drum bag