I go to the fabric store and look throught the pattern books.
To make some of the very "bestest" doggie toys, you don't need a pattern. One of my favorites is a toy I made for a gift exchange a long time ago. I cut two hearts out of fleece and and put a squeeker in each. I covered a short piece of 1" wide elastic with fleece and sewed one heart to each end of the elastic. Very cute Very easy and the dogs LOVED it! You could do the same thing with a bone shape.
You can go on line and find all sorts of goodies -- dog bone shapes shoe shapes, any simple design will do.
The main thing here is to HAVE FUN! and be creative. Chances are even if the toy doesn't look exactly like you had in mind your furkid will love love love it.