First of all, the sensitivity of the mouse and the preference in choosing the model and manufacturer of the mouse is different for everyone. In this article, I will talk about the correct mouse settings for CS: GO. Without the right settings, your scope will be located anywhere but where you need it.
Equipment you need
You should have a gaming mouse and a pad for it. Everyone has different preferences and tastes, which means that you have to choose what suits you best. You need a large gaming mouse pad because it is preferable to play with a low mouse sensitivity
Setting the correct mouse DPI
In fact, this is not the "correct" DPI settings, these are the settings that most professional players use. The normal DPI value is selected from 400 DPI and 800 DPI. You need to choose one of these values because these two values are the most accurate and do not affect mouse movement. All values below / between/above them do not provide 100% accuracy. There are people using 1600 DPI, but this is just a preference. You can easily change the DPI value of the mouse in the software that comes with the mouse.
Why is low DPI and sensitivity better (why 400/800 DPI)?
The reason is quite simple. In Counter-Strike, you need to aim for perfect targeting accuracy, literally on a single pixel. And then the low DPI and sensitivity help a lot. You will not be able to perfectly aim the scope if the light movement of the mouse makes the scope jump a lot, so set the sensitivity low. Also, the reason for using 400 or 800 DPI is quite simple, these are the native settings of most gaming mice. If you do not use the native DPI settings of the mouse, your cursor or sight in the game will not be instantly pointed to the place where you need it, it will be slightly out of place, and this is what you want to avoid at all costs.
Stick to one sensitivity
This is the most important thing. Your body has a "muscle memory". This is the memory of the muscles about how to do something. In Counter-Strike, this is a memory of how far you have to move the mouse to move the scope in the game to a certain place. You don't have to constantly change the sensitivity in the game. Choose the one with which you do not feel discomfort and stick to it, the only way your muscle memory will remember the movements.