This can be very difficult! Once, when I was in high school (c. 1984...) lit a 1/2 gallon of ice cream on fire using the broiler to thaw it out. I find it useful to have "a thing", like "medicine food" and just use that to treat lows. I use a mix of Smarties (dextrose) and Starburst Jelly Beans (yummy+ texture) as it's handy to use for running (in little bags from the craft/ hobbby store) and are tasty, I don't mind eating them but I can just have a few pretty easily. by practicing, I've kind of gotten a feel about using them effectively and avoiding the rebound highs from overtreating.
Here's a pic of a bag of beans, before I started mixing in Smarties, since they work fast.