I just mix up what I need.

Water 600ml
Part A 40ml
Part B 18ml
Part C 40ml
Starter 25ml
Water to make 1000ml

Bleach Fix
Water 600ml
Part A 140ml
Part B 200ml
Water to make 1000ml.

Since all of the unused chemstry stays as the concentrates the shelf life will be as long as possible.