I've thought about cutting my own mats, but have decided against it for the following reason. The prices of mats cut to order has dropped dramatically with the introduction of computer controlled mat cutters. I can get a perfect custom cut mat, made from 1,7mm acid free museum board, 30X40cm with the beveled window cut exactly to my specifications (and NO over cut corners) for about $5 a piece, but the price drops with the more you order. I just received a delivery of 20 mats in the dimensions mentioned above, including 20 acid free mounting/backboards for about $120 including shipping.
Compare these prices with the price you would pay for the raw matting board materials, the needed equipment, and the waste involved in learning the craft. I'll keep ordering mine. It's a tax write off anyhoo...
I don't use a mounting press, though I wouldn't mind owning one. I go with the acid free hinging method and an over mat.