Preparation
Find a few flat kitchen or bath sponges, at your home or at a local store, to build a toy truck for an infant. Use sponges that do not have the scratch pad on the back, so the truck has a consistent, soft texture. If you choose sponges from around your home, ensure that they are new because small children tend to put their toys in their mouths. Avoid getting the sponge wet before use to prevent germs and dirt from settling inside.
Locate a single sheet of plywood from a store or scraps of thin pieces of wood from around your home. You do not have to follow a particular truck pattern for a homemade toy, so even if you only have a few pieces of plywood, you can still make a nice-looking toy.
Sponge Truck
Use one rectangular sponge for the base of the truck. This part will act as the bed of the truck and hold the front cab. Build the front cab by cutting the next two sponges in half or in thirds. If you cut them in half, the truck cab will take up half of the space of the bed, or if you cut them into thirds, the truck bed will be long; this step is entirely your preference. Attach all four sides of the cab to the base sponge with a simple oversewing stitch. This type of stitch holds the two pieces together with a simple looping technique. Pull the thread tight enough to keep the edges together but not too tight so the thread pinches them together. If you want to add windows, now is the time to do so. Cut windows on both sides of the cab and in the front if you choose. Sew the roof piece to all sides.
Cut four circles from the extra sponges and use any type of stitching to attach them to the base of the truck. Put one pair near the back of the truck bed and the other under the middle or near the back of the cab.
Wood Truck
Use a long piece of plywood, approximately 8 inches long, for the bed of the truck. Find or cut similar size pieces for the sides and the back of the cab, and attach them near the front of the base of the truck. Use a piece that is half the size of the sides and back, and screw or nail it into the front of the cab. The open part above the front panel is for the front window. Saw away small sections of the cab sides for the windows and attach a piece for the roof that is the same size as the cab sides. Cut four, same-size circles from the extra plywood for the wheels and attach them to the truck bed.