Conditioner once a week
To be fair I also put Moroccan oil on while my hair is drying.
I use the Treseme conditioner but going to experiment with a conditioner that comes in a bar rather than in a plastic tube to cut down on waste. I make sure I give my scalp a good work with my fingers when I'm washing the conditioner out.
I'm very on it with my lifestyle and what I let touch my hair, silk pillow cases only, silk lined hats if I'm wearing one, use an old cotton shirt to dry my hair, even watch what I'm wearing on the top half my body and what materials my sofas and chairs are made from to reduce split ends where my hair meets it.
I do want to branch out from the routine a bit and try gels and stuff but what I like about the way I've approached it is that it's so low maintenance. I know you can do things like get a filter for your shower head so I might try that first before adding stuff to my routine because it's just another passive thing in the background.
My lifestyle/work life fluctuates a lot and you can definitely see a massive difference in how your hair behaves depending on where you are and what you're doing.