The Fein Mutltimaster multitools (used to) come with a big tool case which has two black storageboxes for accessories, blades etc. 
Note: this is for the older style Fein casesm, not the more recent L-Boxx.
To find a blade, I usually rummage throught the contents or dump everything out on the table.
 Hopefully these dividers will keep things a bit more organised :-)

I made two versions:
A divides into three compartments.
B has some smaller compartments to fit the 65 mm and 32mm wide blades.

I recommend to print upside down, there is a fillet on the bottom.
The divider slides onto plastics ‘studs’ that are inside the storage box, so it only fits these specific boxes from Fein.
 
I'm just starting with Fusion 360  and 3d printing; any comments, tips or suggestions are welcome.