This is the opposite of the turn the ketchup bottle upside down (and thereby stimulate consumption). Make the hole smaller and use only what you need.

I believe more shampoo is wasted than used sometimes because the shape of the bottle promotes tip-over and the my family seldom actually snaps or tightens the lids. It just lays there on its side leaking until the next shower.

My washing machine installer told me to use only half the amount of detergent that is recommended on the detergent bottle. I.e., half of the cup formed by the cap on the large plastic bottles sold by the major makers, not a full cup. It's worked for me.