Originally Posted by
nematers
Ahh the good old "
pinching the tires with my fingers" method. Definitely on the list of my options 
used that as a kid before I even knew how to use the gauges Thought this time might go a bit more serious, but I agree this method has its pros.
Some years ago, I saw a recommendation to squeeze the sidewalls with thumb and index finger, instead of just pressing down on the tread with a thumb. This gives me a better idea of the tire inflation. I've pumped up my various tires, then did the sidewall squeeze to help remember what good pressure feels like.