This one came to me in a flash of brilliance (they’re very few and far between!). I use Tippex to ‘write’ on my feed bins, it’s very clear and easy to read (unlike permanent marker on dark-coloured bins) and if you decide to put something else in the bin, you can just scrape it off with a blunt knife, and start again.
My bins are ex-council wheelie bins, they were all dirty or damaged and had been returned. I paid for them and spent an afternoon with scrubbing brush, bleach and hose, and ended up with fantastic vermin-proof bins. The big ones hold about 6 x 20kg bags of feed, or 1 of Graze On or Readigrass. They’re excellent for taking to events too, full of rugs for example, very easy to roll on and off the lorry and secure behind a partition. They are also great for rug and kit storage at home.