I like to ride my motorcycles up into to the Santa Cruz Mountains and hike on various trails for several hours at a time. That requires that I leave my jacket, helmet and riding over-pants attached to my bike in the parking lot while I go hiking. There are lots of locking cables on the market, both in motorcycle accessory stores, outdoor gear stores, hardware stores, etc. I use one that has an integral combination lock, about 24" long. I run it through the sleeves of my jacket the waist of my pants and the chin guard of my helmet. I run the cable through the handlebars, where they pass between the bar mounts, and pile everything on top of the gas tank. So far, I have never had anything stolen, although I have been following this procedure for years.
By looking around you can find these cables for between $10 and $20. Some cables come coiled up and will fit in a jacket pocket. There are so many different types of cables that you are sure to find one that will be perfect for your use to secure your riding gear to your motorcycle.