How to structure an inventory list you won't regret
One row per thing, one column per fact.
Resist merged cells, colour-coding as data, and notes columns doing five jobs. Name, location, quantity, unit, minimum, value, serial - each in its own column - is a list that sorts, filters, and one day imports cleanly into real software.
Separate 'how many' from 'which one'.
Quantity stock (200 screws) and unique items (THE laser level, serial 8842) behave differently. Give unique items one row each with a serial; give counted stock a quantity column. Mixing them is the spreadsheet mistake that hurts most later.
Locations deserve their own column.
'Warehouse / Shelf 3' as a consistent path - not prose like 'back room, next to the paint'. Consistent locations are what make counting by walking possible, and they map one-to-one onto folders when you outgrow the sheet.
Track minimums from day one.
A minimum column turns a passive list into an early-warning system - even in a spreadsheet, a conditional-format rule on quantity < minimum is a poor man's low-stock alert. (In ItemTally that column becomes real alerts on the Today page.)