This is what I use: In the photo below is an 8" quick-release rubber tie, with the SAK for size reference. When needed, I simply wrap the QR tie around the downtube and the front wheel. Takes maybe 5 seconds.
Price: about 50¢
Weight: negligible
A couple of these live in my handlebar bag, along with a collection of zip-ties and 3 or 4 of the 4" QR ties. The latter can be used to wrapping up my rain jacket, or (with a tent peg) anchoring a tent vestibule sheet against a wind, etc.
The advertised use of these QR ties is to hold grape vines, etc., against a post. They range in size from 2" to 12".