Here's a funny tip I got from a pot dealer with his ghetto ride as we were both on a train one evening. He asked about my Kojaks, and if I worried about getting flats. I told him their okay for commuting, but not particularly puncture resistant and said I try to stay away from bad roads.
So he told me he bulletproofs his tires by shoving a second tire within a tire, cutting the wire from the inside slick. Ghetto, but for him it works and at no cost. He's not so worried about weight or drag of the tires, but he won't let anything stop him from getting busted or worse being ripped off and killed. He said even if the tubes pop inside, the stiffness of the tires allows him to keep riding.
He also told me his preference is single speed is best for him, nothing to wrong gear, jam or chain slip in critical times, but depends on what bike he happened to have stolen at the time!
To this day, I'm still wondering why he shared that bit of those commuting tips to me, but I have since kept an eye out to avoid the same train with leery riders...