How to Make Compartments in a Chest Freezer
Assess the size of your freezer and the volume and shape of the items you will store in it. Consider whether you always plan to use your freezer for the same purpose, or whether you anticipate your storage needs changing over time.
Measure your freezer from front to back and from side to side. Make a drawing of the compartments you want to create, based on these measurements and your assessment of your storage needs.
Cut sheets of plywood or thin plastic to divide your freezer from front to back. They should fit snugly and go almost up to the top, allowing room for the freezer to closer. Cut as many sheets as you need to divide your chest freezer into the number of compartments you want to create.
Purchase, find, or build baskets that will fit in the compartments you have created, and stack neatly on top of one another. They should be made of thin, lightweight material to take up minimal space and allow you to lift and rearrange them without hurting your back.