I use a mix of strategies depending on the target platform. Right now, for nearly all of my hobby projects, the target platform is an old processor running on a

I use a mix of strategies depending on the target platform. Right now, for nearly all of my hobby projects, the target platform is an old processor running on a weird game system without enough memory to run a real debugger and with no ability to expose that debugger's state to the PC. In these cases, I can't even really use printf (where would it print to?) and must instead rely on painting the debug information to the screen somehow. It's a wild and wacky set of techniques. Of course, I pair this with a modern emulator for the target platform where I can at least see my disassembly, set breakpoints, watch memory values. But when I'm working on some issue that I can only reproduce on hardware, we get to bust out all the fun manual toys, because I just don't have anything else available. On the very worst days, it's "run this routine to crash on purpose and paint the screen pink. Okay, how far into the code do we get before that stops happening? Move the crash handler forward and search. (Each time we do this we are flashing an eeprom and socketing that into the board again.)"