I've been trying to figure this out too as I want wash it less in winter... and this is what I've found works best for me so far.

- I condition with something very moisturising (in my case Biolage conditioning balm).

- I apply a lot of leave-in (MOP mixed greens cond) because if I don't my hair looks like straw.

- I apply a few drops of coconut oil as a sealant. Naughty, I know.

- I let it air dry most of the way.

- I blow-dry then straighten.

- If I need to tie it up I use a scrunchie and tie a low, half ponytail so I get a bit of a messy wave at the bottom.

I find if I don't use silicon I can go a week without washing it. I've just got to figure out how I'm going to PT (either by using a PT or cowashing with a conditioner that has protein).
Hair Type: Fine, 3a
Cond/LI: MOP Mixed Greens
Styler: IGA Gel
Oil: Coconut
Overall: Just likes a bit of TLC