You can make your own router template in a few different ways. One way is to use a piece of plywood or MDF that is at least 1/2 thick and has a smooth, flat surface. Cut the plywood or MDF to the size you need for your project, and then use a router with a flush-trim bit to rout around all four sides of the template. Another way is to use a laminate trimmer with a carbide-tipped bit. Set the depth of cut on the laminate trimmer so that it will just barely cut through the laminate on your countertop. Use double-sided tape to attach your template to the countertop, and then rout around all four sides of the template.