If you mix stock all in the same day. I would mix in order, dev, stop, fix. Rinse well after mixing each chemical. Never had a problem. If you are concerned, just get 4 plastic buckets from the dept store and mark them; dev, stop, fix, other. And use them dedicated to each chemical.

For developing, smaller quantities, I just used the 16oz plastic measuring cup for mixing and holding the chemicals, each is labeled; dev, stop, fix, hypo clear. If I was mixing smaller quantities, such as Rodinal, then I would take out the small graduate cylinder to measure that. Then into the 16oz measuring cup. This was back when I was in high school, the 16oz plastic measuring cup was a lot cheaper and affordable for me than a photo graduate.