In general, a home studio can be built in which we maintain an A=B=C ratio. An equilateral triangle between the listening position and the speakers.
A home studio is often a small enclosed space. Here, you want to bring the resonance time to a low level in this room (0.3-0.4 sec).
It is a good idea to add absorption to the ceiling above the listening position. Ideally combined with a rug under the listening position.
You also add absorption on the front and sidewalls. Often also on the rear wall.
Bass straps are placed in the corners to make the low-frequency sound better.
You can also place diffusers on the sidewall to spread annoying reflections instead of dampening them.
Every situation is different and the correct solution may deviate from the mentioned recommendation.
In this example: