I have one coat closet in my classroom. For the first part of the year that was sufficient. Anytime my students needed to get into their backpacks it became a bit of a nightmare, but worked fairly well. Once winter hit and everyone was wearing heavy coats, it all fell apart. Students tossed backpacks and coats into our one coat closet and they spilled out everywhere. The coat closet is just inside our door so they were always in the way. It drove me insane. I had to do something about it before I starting throwing coats and backpacks into the hallway, immediately followed by their owners.
I got two big tubs and put them on the sides of the classroom for backpack storage. Two tables put their backpacks into one tub and the other two tables put their backpacks into the other. Sometimes these tubs are neater than this, but they at least contain the backpacks.
That left us plenty of room for coats. I'm slowly training the kids to hang their coats up on the back row of hooks if they are the first ones in. So far we've only had a few coats land on the floor throughout the day. There's also a basket hidden in their to hold hats, scarves, mittens, and other random cold weather necessities.
I'm not sure what it says about me that this was so critical to my sanity. Regardless, it has greatly improved my attitude throughout the school day. That's worth a lot.