Treatment sequence

There are so many different hair products on the market that it's hard to figure out which product is most effective and in what order just by looking at the names. So, I usually follow the routine of shampoo, treatment, and conditioner, but since I apply the treatment while washing my hair, it's a habit that's hard to maintain for long. I was wondering if I should apply the treatment after I've finished washing my hair, or if there is a specific order for using treatments.