I've started my inventory and am making refinements to the system as I go along.
This is where I'm at.
Each painting I will give a number , and pre-fix it with a letter to denote loosely the category it fits into, for example s for seaside, b for boat and r for random.
On the back I write when it goes out to a gallery or exhibition or competition and the price asked. When it comes back I tick it.
I have two boxes, one for available work, the other for work that is out or sold.
Digitally I am creating a file called Ultimate Inventory where the very best image of my artwork goes, labelled by identification letter and number, my name, title, medium and size.