Thanks for these great tips.
There's one tip here that I must disagree on, and that is: Do NOT use round containers if you don't have to! Rectangular and square shaped containers are the most space-efficient containers you can get.
Think about it - if you put 4 square containers next to each other, and then 4 round containers next to each other - which one wastes less space? See what I mean?;)
Obviously, it's not always possible to use 4-sided containers, but if you're already investing in new containers, do try to find those instead of round ones.
Happy cooking and organizing!:)
Square, rectangular - but NOT round!