Here are the most important two tips I learned from many many years driving BMW's that didn't have run-flats and didn't have a spare either. Just a can of fix-a-flat, a compressor, and a prayer book/user manual.
A) get a plug kit and know how to use it
B) that's it there's no B
A plug kit (as in, an actual kit, not just the one you grab off the shelf at harbor freight, I'm talking that plus a knife, pliers, a compressor, and a jack/tools to get the wheel off if necessary to facilitate) is going to get you out of 90% of puncture issues. 10% of the time, you'll have a gash or something that a plug kit can't help with. half of those gashes, the fix a flat might help hold enough air to limp it to where you're going iwth frequent air stops. The other 5%, you'll be calling for a spare/tow.
But, if you have a plug kit and a fix-a-flat kit, 95% of the time, those will be enough to work every time.