Wet pan with sauce, then lay down a layer of noodles.
Add 1/3 ricotta mix. If using other fillings, either add 1/3 of each, or put each filling in a different ricotta layer. Sprinkle with Mozzarella, then dab sauce over top and add another layer of noodles.
Repeat until pan is full (2-3 layers), finishing with noodles and sauce. Let sit for half an hour if using no-bake noodles. Then cover with foil and cook until fillings are hot and bubbly, noodles cooked.
(You can also add the mozzarella now, but you have to watch it more carefully to prevent burning.)
Add a layer of mozzarella and either freeze for later, or return, uncovered, to oven until cheese is melted and toasty.