In your experience in training athletes and yourself, what strength methods would you say are the best for gaining strength fast.
There is no one definite answer to that because each athlete is different. Training methods are like school classes. One class will be too much for some students (e.g. a university course for a high school sophomore) while some others will not be stimulating enough to increase the student’s knowledge (e.g. a Ph.D. candidate following an HS english class).
Same goes with athletes. A beginner will progress from the simplest techniques, advanced methods will also give them results but not more than the basics. And since a training method will eventually stop producing results, if you use a super advanced method when you don’t need it (because you want super gains super fast) you will shortchange your long time gains because that super advanced method will not be effective anymore when you really need it.