If im training for strength i increase weight once i can do 2-3 sets of 6, i add enough weight so i can do a set of 4 and usually do 4x4s and try to increase reps from the last set to the first.
If im doing hypertrophy, i just lower few kilos so i can do 3-4 sets of 8 and add the dropsets, res-pauses, etc. Don't really focus much on progressive overload when on hypertrophy, i just try to kill the muscle. But i do increase weights if im reaching sets of 12+.
I cycle strenght and hypertrophy programs, and sometimes mix them.
I find it's very important to have a very regular schedule, keeping the order of exercises, keeping a timer for the rest periods, and keeping track of other activities outside gym, diet, etc. I just started swimming for the summer and all the lifts took a hit and had to eat almost 1k extra calories to survive.
I also had this indicator of how strong i was on a certain day, for example i would start doing pushups, if i reach 50 non stop as warmup and had some in reserve then i knew that day i was going to increase reps on my BB bench press. If i reached 50 but didn't have much left then i may not increase any reps, and if i didn't reach 50 that day i would struggle reaching the reps planned for that day. You get the idea, haven't found other warmup exercises that would tell me how well i would perform on the main lift for other lifts, but for bench press it works like a clockwork.