Another way is to try reversible cross stitching. It isn't as complicated as you think. When you begin you work the first part of the stitch like normal BUT to skip the next stitch. Basically you do one skip one. When you get to the end of that row - work back and finish the stitches. When back to the beginning start the next row putting the stitches above/below the skipped spaces (like a checker board) Repeating the process. To fill in the 'blank' spaces just start over from the beginning.
I have found that using these methods use at least double and sometime triple the amount you would use if you did a regular cross stitch and had a messy back.
I hope that this helps