Rubber is a type of polymer that stretches back to its original shape when bent or stretched. It's made from latex, which comes from a tropical tree. All you need is a few things from your local hardware store to drill rubber. Most of the items might already be in your home. The most important part of drilling rubber is to keep it from moving during the drilling process.
Mark the desired drill area of the rubber with a permanent marker.
Place the rubber onto the work surface. Insert the rubber between the work station and vice. Tighten the vice to keep it stable.
Choose the appropriate drill bit for the size of the hole. Choose a drill bit that's smaller than the desired diameter of the hole. For reference, choose a 1/4-inch drill bit for a 3/8-inch hole. Rubber stretches during the drilling process.
Insert the drill bit into the head of the drill. Tighten the drill bit with the torque key that comes with the drill.
Place the drill bit onto the mark and drill the hole slowly.