Remember that the directions for how much of a product to use are put there by the manufacturer, who has a certain vested interest in the consumer using more. Where do you think those “wash, rinse and repeat” directions on the shampoo bottle came from?
Here are the things I’ve been able to cut my use of by 1/3 or 1/2 with no noticeable difference in their effectiveness, although I’m certain the possibilities are endless:
liquid hand soap (half a pump works just fine)
I’ve also found that the Downey fabric softener ball works just fine with generic fabric softener inside and that when my Swiffer Wet replacement cloths ran out I could substitute a washcloth and a vinegar/water solution.
A lot of these reductions and substitutions can have positive environmental impacts as well, which is an added plus.