Below is the template I use for making my matchboxes. It's finished size is 5x7cm's but you can scale it up or down depending on what size you want. Copy onto whatever material you need/want, cut out and pre-fold all the folds. I start by folding up the long edges, I glue the flaps to the inside of the short flaps, then fold over the edges and glue the flaps on all four sides to the floor. For the lid, just cut out, fold and attach. You may need to adjust the size of the lid depending on the thickness of material used. Better to re-measure the inside part first. Hope all this makes sense!