CUT your used jeans. Many pockets can be very useful.
FOLD jeans in sideways. This is a key. I feel like this is cuter than looking at a front. Also if you open the zipper, your cutie puppy can fit in there and look outside with you:)
Inside out and SEW.
CUT out the fabric left (leg part) and make 2 straps. Sew it behind the belt line and make sure you sew on the pink area so that thread can be hidden well.
Decorate anywhere you want! I used laces, fabric, and matched buttons. It's "the fun" part!