Drink more so your stash gets smaller. Trust me it does not work.
Buy less tea. I can neither.
Label your tins, place them sorted wherever you keep them, if you can.
A kind of database app, as for cd’s. I’m not into apps but I remember seeing one for tea a long time ago.
Sorry, a spreadsheet seems to be the simplest solution that I can come up with this morning. What fields do you use (type, name, date of buying, tin I keep it in, place of buying, I should add more fields)?