A great way to save on printing and paper and is to make your own reusable worksheets. These worksheets can be a great way to occupy littler ones while you are doing school and helps them develop their fine motor and pre-writing skills. They can also be a great way to introduce mazes and connect the dots and will really stretch one workbook or activity book into hours of extra fun.
All you need is a 3 ring binder, some sheet protectors, and dry erase markers. Select the worksheets or printed pages that you would like to use, slip them in the sheet protectors, and then set your little one loose with a dry erase marker (but make sure they are wearing play clothes or a smock, since dry erase marker usually will stain clothing). The Dollar Tree is a great place to find workbooks that you can take apart and put into the sheet protectors, and they even have some workbooks that have the dry erase board built in. I got a great Disney Princess alphabet book there that teaches how to write the letters and my 3 year old girl loves it (even though she can't really write the letters well yet). I also printed out dotted outlines of shapes for her to trace to help her with her pre-writing skills and some worksheets where you circle which picture doesn't belong in each group.
I love the reusable worksheets because the pages that I've already printed for my older son are now being used for my daughter and I didn't have to go searching for sheets again and reprint everything. As the kids grow, you can switch out the worksheets in the sheet protectors. So the initial cost of the sheet protectors is well worth it for how long they last and for the many different uses that they serve.