Firstly we have to remember that tretinoin is an acid form of vitamin A. So avoid 2nd gen copper (GHK) when applying tretinoin as they can be damaged by acids.
Other than that... most products are fine. If you have the prescription Gel ... I would apply that first .. or, right after a thin serum.
If you have the prescription Cream... I would apply that after any serums and then follow with your other creams if you wish.
Also... some like to apply their tretinoin first and let it soak in for 15 minutes or so. IF you fall into that category, after your wait time .. go ahead and layer products as you would on clean skin. Here is the way to layer:
Alcohol based serums + Water based serums + Creams + Oils