Pre-workout boosters are the most frequently used supplements for the goal of performance-boosting.
These products contain a variety of stimulants, with the most common ones being caffeine, beta-alanine and l-citrulline.
And though they are quite effective, pre-workout supplements should not really be at the core of your plan, nor should they be used too frequently, due to the massive amounts of caffeine (4 cups of coffee worth of caffeine in 1 dose).
For this reason, you should rely on proper workout stimulation, as well as proper recovery (food/sleep).
THIS is how you will optimize and improve your performance.
Nevertheless, if you like pre-workout boosters, use them!
Just make sure to use them appropriately, on your hardest workouts or, days when you need an extra kick in the butt!