The solution should meet these points:
-save the space of your room
-preserve and keep safe your miniatures
-find quicky what you need during a game.
There are a lot of different solutions...in the pictures below, is just how I store my minis..
the black cases have a double face and are easy to move. I divide miniatures for type..for example Demi-Humans and inside the case I divede between Halflings,Dwarfs, Elfs,etc..
the last pictures show an old typographer's cabinet that I use for metal and resin miniatures