In my years of experience I've realized from personal usage results and from forum/IRL feedback that drug response is different but we can group a lot of drugs together and then pick whichever one we respond best to of the lot for the same overall benefits. Let me break it down a bit; Here are the groupings of drugs that all have almost the exact same functions:
Dbol, Anadrol, Superdrol
Tren, NPP, Deca, Trest
Anavar, Tbol, Winstrol (oral)
Equipoise, Masteron, Winstrol (inj)
Mtren, Halo, Milbolerone (prob spelled wrong)
Basically you want to figure out which of the drugs in each grouping you personally respond best to and then just continue running that one because they do the same thing roughly in each grouping but you're just sacrificing results if you go with one you respond less to.
So for example:
Lifter A responds best to Dbol, NPP, Anavar, Mast, Milbolerone
Lifter B responds best to Anadrol, Trest, Tbol, EQ, Mtren
Both should make all of their cycles some combination of Test + any of those 5 drugs for the rest of their time using gear. Sure, they *can* use another one but it's just not gonna be as efficient.
Once you know what you work best on, just keep doing it. Personally I respond best on Dbol, Deca, Anavar, Winny, Halo. The others seemed to provide less overall benefit based on training logs/meet performance at the time I was running them, or had some sort of effect I disliked which made them undesirable. I know that if I stick with these I am guaranteed to have a good, productive, comfortable run until I cruise again.
To go further: Narrow down your effective doses. Did 50mg/day of Dbol work better than 25mg/day? Did 100mg/day actually help any more noticeably than 50? etc, figure these things out. I have gradually reduced doses from when I began to now (Most people can do this as we need less and less to maintain existing performance/physiques and build on them btw) and I can now peak for comp on a cruise dose of test, 25mg/day Dbol PWO, 300mg/wk Deca, 50mg day Var PWO and I do not necessarily *need* Winny or Halo at all but I know they will help if I feel in the last week of prep that I'm not prepared for my projected 2nd or 3rd attempts for any reason.
Logs are your friend, keep notes of shit in whatever way makes most sense to you.