I reuse old cardboard boxes and use a sharpie to label the boxes.

I then place the boxes on one or two sets of shelves if the parts are not specifically dedicated to a specific car.
If the parts are for a specific car that is not being driven I place them in the car.
I have a specific shelf for parts to be installed on cars being currently driven.

Even with that I forgot stuff I had and ordered/bought stuff I didn't need because I already had one.

I do not have a spreadsheet but it would probably be a good idea for those that have to deal with my stuff when I kick the bucket. A lot of my stuff just looks like junk to the average person. T/A Steering Gearbox, AAR/TA, washer squirters etc.