Make sure your shaker bottles are completely dry on the inside then just put the powders in so they're ready to go.
That's what I do, problem solved easy as.
Powder supplements like pre-workout and protein
Being somewhat OCD, I can't do this. I have to add powder to the liquid vs liquid to powder. IDK...I'm fucked up.
OP-freakin Tupperware dude. The smaller 1c containers are perfect for 2-3 scoops of protein.