Mobility training is pretty simple. Spend more time in the position that you are trying to achieve, and make any alterations that you need to get there.

Keeping your workouts simple makes it easier to focus on your goals, and makes it easier to continue showing up.

Getting stronger is a skill, and is no different from any other form of skill acquisition. In essence, progressive overload is the manipulation of some dimension of training in order to keep the exercise(s) challenging.

Strength training at its core is relatively simple.  There are five fundamental movement patterns that, when done two-to-three times a week, are more than enough for most people.  These movement patterns are: Push, Pull, Hinge, Squat (including lunges), and Carries.