The Random seed pot!

I use some old packets for microgreens. Same with some veg varieties I've tried but wouldn't grow again

Same here - I'm planning on sowing plenty of trays of lettuce, rocket, spinach, oriental greens, leaf beet, pea shoots, etc in late summen/early autumn to overwinter in my conservatory (basically as soon as it's no longer too hot in there). Some I bought specially for salad growing, some are magazine freebies, some will be the inevitable eleventy-billion lettuce seeds that are due to expire in the next five minutes!

With any luck I'll get a steady supply of baby leaves for salad - they cost a fortune in the shops and go off really quickly once opened, so it'll save me a lot of money for very little effort