Put away some toys temporarily. Take them out in a few weeks or months and put some others away. This will be beneficial in several ways. Your kids will love the "new" old toys you just brought out! It will be a happy reunion. Also, it will help decrease the clutter around your house. If your child misses a specific toy that's out on toy "vacation", by all means, bring it back early. Also, don't put away any of your child's "lovies". This idea is not meant to deprive your child of anything, but to help restore the novelty of the toys.
Homemade Play Dough
This stuff is just as good as store bought and costs a fraction of the price. Also, decreases the amount of packaging you purchase. It only takes about 5 minutes to make!
1 cup all purpose flour
1/2 cup salt
1 teaspoon cream of tartar
1 Tablespoon vegetable oil
1 cup water
food coloring
Mix together and cook in a saucepan over medium heat. Continue stirring for 2-3 minutes until it forms a ball and pulls away from pan. Divide into smaller amounts. Place few drops of food coloring into each amount and work into dough thoroughly. Store in airtight container.
Homemade Bubble Solution
This will also save you lots of money.
9 parts water
1 part dishwashing liquid (Joy seems to work the best)
1/2 part glycerin (sold in pharmacy departments)
Mix well.
Crayon Bits
What to do with all those little stubby crayon bits? Melt them together in a small microwave safe container to make a big psychedelic crayon. Heat slowly in 10-20 second increments and monitor closely. For more advanced crayon making, use a candy mold (again monitor carefully in the microwave, the mold can melt). These make great favors for children's birthday parties.