I've been growing my Tolkien collection lately and started to feel the need to make an inventory of it before things got out of hand.

Subsequently, I made a spreadsheet that has grown from 4 columns per book entry to about 10 columns per entry and it feels that the more books I have the more information I need to capture for each (especially to distinguish Fine copies from non-Fine copies). However, there's now so much information that the spreadsheet has become impractical.

I was wondering what's the approach of more experienced collectors to this and if you use any specific software tools.