Dirty woodstove glass? Try dipping a dampened piece of newsprint in the fine white ashes after your fire has died. Whipe it onto the glass in circular motions - it works well if the glass isn't terribly dirty to begin with.
If you have ever tried to cut or trim veneered pieces like a door, you know splintering can be a problem. A solution is to use a utility knife with a new blade and a straightedge to mark the cut line deeply on both sides. Some carpenters also use masking tape before making the knife cuts to stabilize the edge and protect wood from the saw making the final cut. Most important is to have a sharp fine-toothed blade in the saw.