Great idea. I keep a small iron next to me at all times for pressing seams after I sew them - didn't think of doing it before I sewed them, though.
I made an ironing board/rotary mat from a warped rotary mat and a piece of plywood. It was a 16x10 mat that warped in my car on the short ride home from the LQS. I cut the board in half and used the warped side. First I covered the board with a layer of that aluminum foil, next cotton batting and finally some cotton duck fabric which was cut 1.5 inches bigger than the board and glued to the back-side of the board. Next, I cut the mat the same size of the board (8x10)and used a really strong glue and glued the WARPED side of the mat to the board. I let the board dry on a flat surface under a large stack of heavy books. When it dryed the mat was flat as a pancake.
I've been using this rotary mat/cutting board for at least 15 years now. I keep it in my sewing bag and take it to classes and never have to worry about my mat warping again. It saves space and I can cut or iron in a much smaller space and not have to wait for my turn at the iron or cutting board.