For leftovers, we use these glass containers with locking seal lids called Glass Lock containers.
As a bonus, it is available in small, medium and large and also a range of colours, so you can match it up to the rest of your kitchen.
So learn from my mistakes and always check to see if your seals are still in your lid before assuming that your bucket is airtight! A removable divider separates the contents or can be removed to store larger quantities of one item.