Let students write directly on desks with dry erase markers. They seem to love "doodling" and doodling their math on desks makes great sense!
This strategy of monitoring students during independent practice is the same as using cups ... but this is cheaper ... easier?!? Use construction paper!
Do you have wall space under your whiteboard or chalkboard? Do you have supplies, manipulatives that you want to be very accessible? Then hang baskets - with command hooks!
Buy "fat" straws! Use colorful duct tape to tape the straw to each desk. Put a pencil in the straw. That way there is a pencil for each student daily.
Take a few minutes to hot glue pom poms on dry erase markers that you use for teaching. You'll always have an eraser handy!
Buy socks cheap - dollar store cheap! Buy the kids' sizes. Buy black! The make great erasers for dry erase markers!