As your LEGO collection grows, you will ultimately face the question: what is the best way to sort LEGO?
There is not one answer to the question of sorting LEGO, but there are ways that work better than others according to the size of your collection and your building style. For LEGO storage solutions head over here, or continue reading below for LEGO sorting methods you might consider:
➡ SORT LEGO BY SET: using this method you would keep all the LEGO parts together that belongs to a set you may have purchased at a retail store or online.
PROS: the benefit of this LEGO sorting method is that you could easily rebuild the original set. Also, if you intend to resell the set, it is best to keep it together.
CONS: the downside of this method is that if you are building your own creations it becomes very difficult to remember which set a needed part is in. Also when you disassemble your creation you would have to go through each LEGO set inventory to replace the parts to the correct LEGO set.
SUMMARY: this is an excellent LEGO sorting method for collectors who don’t really “play” with their LEGO, or for fans who only build with LEGO according to set instructions. However it is not very practical for creative building.
But even as a free-style LEGO builder you may keep some of your sets together for some special reasons. For example; I collect the small LEGO Creator sets. I do not mix these into my regular LEGO storage system, but keep them in their original boxes.
If you are more of a collector-minded person you might prefer this LEGO sorting method because of concerns about loosing pieces if they are all mixed together. However if you have a nice sorting & storing system you shouldn’t have to worry about loosing pieces. And if you like, you can always keep the original instructions and rebuild it from your sorted and stored LEGO.
➡ SORT LEGO BY COLOR: if you use this LEGO sorting method you would keep all parts together that are the same color in the same storage box, tub or drawer. 
PROS: you can very easily build an all-red monster! 😉
CONS: although you can find colors easily, you may not remember what parts you have in that color. Especially smaller pieces become difficult to find in a large box of various shape and size parts of the same color. And sometimes you just need a particular piece, and it doesn’t matter what color it is. But which box is it in?
SUMMARY: this is the preferred LEGO sorting method for sculpture and mosaic builders, who use very few different types of LEGO elements in their creations, but color is most important to them. However if you have a mixed-style of building it might not be the best choice for you.
➡ SORT LEGO BY TYPE: using this LEGO sorting method you would separate your LEGO parts by type. Bricks go here, plates here, tiles over here… roof pieces in this drawer, minifigs in that compartment, etc. 
PROS: are you looking for a window? You know exactly which drawer or box to look for it! You need that special little part with the clip? Right there!
CONS: if you are building that same red monster, you would need to pull out several drawers or boxes to find all the parts you need in red.
SUMMARY: this is the preferred LEGO sorting method of organization for mixed-style builders. It is very easy to find parts for your creation. It is also very easy to clean-up afterward, especially if you are using a multi-drawer storage system.
➡ SORT LEGO BY COLOR & TYPE: using this system to sort LEGO you would separate your LEGO pieces by both type and color. Those 2×2 bricks that you separated by color in the “color method”, and had all together in the “type method”, will now be separated by both type and color. So, red 2×2 bricks go over here, and blue 2×2 bricks go over there. 
PROS: this is the method used by LEGO fans with a huge collection of parts. Basically they may follow either the type or the color method, and when their storage box or drawer overflows, they split the parts into smaller, more manageable chunks.
CONS: this system can be overkill for LEGO fans that have a smaller collection. You would end up with lots of little drawers with just a few parts in them.
SUMMARY: this method is not something to start out with, but it can be a natural progression from the type or color method as your collection grows.
Keeping your LEGO organized lets you focus on building rather than searching. If you use one of these LEGO sorting systems coupled with a good storage solution from the beginning of your LEGO hobby, you will save yourself a lot of “Where did I put that piece?” kind of headache.
If you start a system later, when you already have a sizeable LEGO collection, it may take a weekend to sort them all out, but it is totally worth it! So go for it! You will be very pleased with yourself! 😉
You may also check out these posts for further ideas:
