A great block idea is to collect milk cartons. Cut the tops off and wash well in hot soapy water with bleach, when dry you fit two cartons together. This is such a tight fit that they stay sturdy for ever. The children love to bring these from home because they are contributing to this activity. We built towers and castles, thrones and highways with these wonderful milk carton blocks and it is a great recycle idea as well.
Lids from liquid laundry detergent bottles make great additives to the block area. Children can put things inside or stack. Ask parents to add to your collection for a variety of colors and sizes.
Ask parents to donate empty cereal, cracker, pop-tart etc... boxes. Fill with newspapers, shredded paper, etc... Tape all edges using masking tape (this just help reinforce it a little). Cover with colorful Contact Paper or construction paper. And there you have light weight blocks that won't hurt the kids when they knock the blocks down. And isn't that what all toddlers do with blocks?
In place of conventional wooden blocks, use laundry detergent boxes, oatmeal cans and other round canisters.
Here's a great idea on how to make homemade blocks. First start with empty tissue boxes. (the square kind) Then stuff the boxes with newspaper and contact the blocks with brightly colored contact paper. Here's where your imagination comes in. You cut out pictures from magazines and contact to all sides of the blocks. (you use clear to contact pictures on ) After that use colored pcv tape to cover edges of the blocks. I have used this idea to make feelings blocks with faces of children happy sad mad etc. You can also make transportation blocks, pet blocks whatever! Have fun ! These are my kids favorite blocks!