The first thing to do is to cut the cardboard into manageable pieces. You can either use scissors, a knife or a pair of wire cutters. The other option is to use a cardboard shredder that will shred the cardboard into tiny pieces. It is recommended to use a paper shredder, but if you don’t have one, you can use a cardboard shredder.
When cutting the cardboard, you should try to avoid cutting it into long strips because these strips will be harder to break down. After the cardboard has been broken down, you can add it to your compost bin. Make sure that the cardboard gets mixed in with all the other yard trimmings and leaves.