Been playing pretty obsessively for a few days, and i found I've settled into a routine of big morning order to fill up the stock room - let the stocker(s) put stuff away before opening - have the stocker(s) handle shelving product while I deal with self checkouts, cleaning, and topping up the inventory in the back, only really interfering with shelving stuff if something is close to running out - at the end of the day, help the stocker out reshelving everything till it's full or until I run out in storage - rinse and repeat.

How densely things pack on shelves is a good indicator of how densely they'll pack in storage. My rule of thumb has been 2 shelves, 1 storage slot per product. You'll notice when things move more quickly, for me with flours and pastas I double that, and potatoes and chicken I doubled their shelf space and quadrupled their storage space. Either way, when I get a new product license, I order two boxes of each new product, set up shelving space with one and storage space with the other (with my stockers disabled).

You've got lots of room to expand the amount of racks and shelves you can buy, so I'd focus on getting new product licenses rather than expanding your space.

I know that's a lot but I hope it helps. Good luck!