Here's a Dinosaur leash and collar I made my dog, Brody, today! It was actually super simple and took no time at all. I had a little trouble finding the hardware for the collar and leash so what I did is buy a very cheap collar and leash from the craft store (they were $1 each) and just cut them up to get the buckle and d-ring (the metal part on the collar where the leash hooks) off. I found the dinosaur ribbon (which my fiancé picked out) at Michael's. I can't wait to make more custom collars and leashes!
Here is the tutorial I used for making them from Sew 4 Home. It is a great tutorial and very informative! I love when tutorials use high quality, detailed photos! There is a ton of info in the tutorial and I found it very simple to follow. She even mentions at the end of the tutorial that a "green" alternative is to use hardware from an old collar and leash. It literally only took me maybe 30 minutes to make both of these. There are a ton of other great tutorials on Sew 4 Home also! There is a seat belt cover I want to make to put on Brody's harness for some extra cushioning under his arms.
The only real change I made was using a zigzag stitch (and going over it a million times) on both places you sew on the leash - but that is because Brody tends to be a little crazy pants and I felt like I needed to make sure it was reinforced really well to avoid chasing him down the street ;)