Solar Noon and a plumb bob will get you true south. Of course you need sunshine ...
a rare commodity these days.
Them make a simple inclinometer, a disk, wood or anything with a protractor scale with a weighted indicator to place on you mount head for the polar axis and adjust it for your latitude. Mine is 36.7 degrees and I use the inclinometer app on my Android Tablet.
A good idea is to mark out a spot for your tripod where you normally set it up with three paint marks or similar so you place the tripod in the same place everytime. Mine is on the driveway out front with a good view south. I've also set up a level base plate that I put down first so I am pretty close to on SCP target before I do any checks and minor tweaks.
So far it has worked well, enough that when I get guiding to work there will be little need to fiddle with it.
Having a good 'setup system' makes for quicker and easier setups with less frustrations for sure.