Keep them in bins or clear boxes with lids with labels. Don’t mix the LEGO with DUPLO or Lincoln Logs, keep a box or bin for each type. If you have lots of LEGO “sets” for individual items like a fighter jet or aircraft carrier, keep those sets outside of your regular everyday LEGO items and put each in their own individual box and keep a photo from the box or instructions inside — don’t discard or you’ll never get it back together again. Teach your kids to keep these special sets together and only take them out when they can keep them separate or with a big brother or sister to help. Mixing everything together just produces frustration because you can’t find the piece you need and results in lots of little parts that are never used again — but you are constantly picking up or stepping on.
Make the system easy for the people who actually use it: visible categories, reachable storage and a clear place for each item to return. For younger children, a picture label can work better than a written one.
My final check is practical: can you find what you need quickly, put it back just as easily, and see when the space is getting full? If not, simplify the categories or move the storage closer to where you use it. An organizing system should make life easier, not become another chore.
Mr. Organized's Answer