I also don't need a straightedge either. Basically it's very easy once you get used to it. With your guitar tuned normally and the neck settled from the string change:
1) capo at first fret, or use your finger.
2) fret around the 15th fret or so
3) look at the gap between the string and the the 8th fret or so.
The gap should be somewhere between a hair and a millimetre. I try to keep the gap small if I can. Loosening (counter clockwise turn) makes the gap bigger.
Before tightening, loosen it a bit first to feel if it's already tightened all the way.
Adjustments take some time to take effect, so take plenty of time between adjustments, let it settle.