If you train hard enough (or not hard enough I suppose) for long enough you will eventually run into a period where progress stalls and improvements to your lifts become much more difficult to realize. Sometimes plateaus last for a few training blocks but, its very easy to let a few blocks slip by and before you know it you are running up on a year or more of minimal progress.
If you ask five different people what causes training plateaus, you will undoubtedly get five or more different answers. The real kicker is each person you ask is probably right! Variables that determine how well you adapt to training are infinite including but not limited to your biological load (any factor that influences physiology from nutrition, sleep, stress, training load/effort, and many other things), the organization of your training plan and how well that organization matches your needs, your physical environment, and many other things that sometimes require complex solutions.
To break through a training plateau, you do not need every single system mentioned above to be optimized. What you cannot have though is a single system dragging down everything else which seems to be the most common factor that contributes to training plateaus. Biological load is probably the greatest influence on the success of a training plan (primarily because the factors that comprise biological load stretch over many different areas). The second biggest contributor is the training organization you follow and where you allocate your energy in the training plan.
Everyone knows they need to sleep more, eat better, and reduce their daily stress but, not a lot of people know how they should change their training organization to break out of the training plateau they are in.
I cannot propose a single system of training to you but what I can do is offer a method that has worked well for me and many of the Coaches here at Kabuki Strength to break plateaus.
Using potentiation is as simple as refocusing your training to zero in on a single type of improvement. Below is one example of non-potentiation for a typical bench press workout and below that is a potentiated bench press program.
Non-Potentiated Pressing Session
Potentiated Pressing Session
As you can see from the two examples we have what I would consider a common upper body session. In the non-potentiated example we have a potentiated example that is still upper body pressing focused but, the direction of loading is very narrow. In the potentiated example we kept four exercises, but the focus is 100% about improving tricep strength in the bench press. This change will provide a very significant training stimulus but targeted at a specific area. The hardest part of potentiating a training plan is letting go of your normal accessory work for the period that you potentiate. Its not ideal but it is a necessary compromise if you want to use this method. If done properly you simply will not have the recovery resources available to potentiate your training while doing all of your normal work. For that reason, potentiated phases of training should last no longer than 3-7 weeks and only a couple times per year. You don’t want to overspecialize for too long as the trade off having a massive unidirectional stimulus is regression in other qualities.
I hope this gives you some ideas of how to jump start your training plan an either mix up your current routine or break through a sticking point.