Since I mainly collect from 4 series (and a few 
miscellaneous), I have a separate book for each 
series plus a large one for my pan cels. The 
books are kept in a dark closet. If I have more 
than one cel of a character they are placed next 
to each other (usually facing each other). The 
rest of the characters are placed by how good I 
think they look next to each other. In the 
miscellaneous cel book and the pan cel book, I 
also place whichever ones I think look good 
together on facing pages.

I keep the sketches separately from the cels. 
They are placed in cel bags (grouped together in 
the same one if they are from the same cel) I 
stack them in order of size (largest on bottom) 
in a large dresser drawner where they can lay 
flat.