Asda £2 glass bon bon jars are very popular here especially with dwarfs who like an enclosed sandbath container.
Baking trays and tins as they are available in different sizes to fit a particular space.
Tupperware for the same reason.
The bottom half of the big round sweetie tubs. You can pop the lid back on when spot cleaning to keep substrate out.
Strong cardboard boxes.
Tip: always have a small sieve handy to remove seed shells and other debris, a small poop scoop to remove clumps of wee and a pastry brush to brush sand back in, off wheels etc.