I am a big fan of Double Progression. It's super simple and works like a charm.
Say we are benching for three working sets. Our rep range is 5-12. It would look like this on a program:
Bench Press (100x10, 100x10, 100x7)
So, we just add reps each workout until we hit three sets of twelve with our weight.
Bench Press (100x12, 100x12, 100x12)
At this point, we increase the load. How much you increase really depends on a lot of things, but for our example we will just add five pounds.
Bench Press (105x10, 105x8, 105x5)
We repeat this cycle ad infinitum, it allows for consistent progress week to week. Sometimes I only get one more rep, sometimes I smash my numbers, but the system remains the same and I still progress.
In short, you pick a rep range for your working weight, and once you hit the end of that rep range you increase the weight and just keep going.
The true magic of this system, especially for bodybuilding and general weightlifting, is that you are milking the weight for all the progress it can give you. Rather than chase heavier weights, you outgrow lighter weights.
For powerlifting and such there are different systems, but Double Progression has always been my bread and butter.