Just lay it flat under you dog, wrap it around the and then clip the straps up around the neck of the legs. My dog is a 17lb bichon.

The straps and buckles look like they would be super durable, but a lot of th seams and stitching only gets the very edge of the straps. Couldn't even test it or try on because the straps were broken.

Back portion also has an easy grab handle and zip-able pocket for spare * bags. I like to be able to latch in the front so the lead tension on the harness will cause him to turn towards me instead of keep pulling forward.