Find your old art projects. Pick out the ones you'd like to see dismantled, reused or recycled. This may be a favorite art project that you'd like to see given new life or one that didn't work out well, but which you'd like to give a second chance at usefulness.
Write a plan for your art project. If you're using several old art projects in a new mixed media piece, you'll need to list the necessary materials and plan the dimensions and creation process.
Research the medium for your new art project, and trouble-shoot any problems that could occur. For example, if you're planning to paste an old drawing onto a painting, you'll need to be sure to paint with acrylic rather than oil, as the oil will degrade unprotected paper over time.
To the extent that it is possible, do a trial-run of your art project, testing the various stages of the project with dummy materials. For example, if you plan to break apart an old ceramic pot and use the pieces for a mosaic, try locating a pot made of the same material--but which you don't care about--that you can break apart. Break the test pot as you intend to break apart the actual art project you're recycling.
Disassemble your old art project (if needed), according to your plan.
Assemble your new art (also following your plan).
Step back and analyze your new creation. Judge it as you would any other creation--examine its balance, structure and design. Look for weaknesses and make improvements as necessary.