I do that with electrical tape. I also keep a small roll of it in my tool bag.
I'm firmly in the no spare tire faction. I've had one puncture in the last 10,000 km. About double punctures - I think I've had two of them in 46,000 km, because I didn't properly track down the reason for the first puncture.
It helps to run on relatively wide tires - 30 mm on my Bike Friday and 650Bx42 on my Elephant NFE. They seem to greatly reduce the risk of punctures.
I ride with one or two spare tubes and patches, but spare tires only in exceptional cases, such as when I headed up that road across the mountains that had been officially closed to all traffic for years, with unsurfaced sections and more evidence of past land slides than you can shake a stick at.
So far I've not yet had to use a tire boot on my own bike, though I helped out another cyclist once.
I've had one cracked frame (on my brother's aluminium bike) and two snapped RD cables during the same time, before I started religiously replacing them every 12 months.