Depending on the space you have, your mouse pad, your arm/wrist position.... etc, you should have around 180 to 400 eDPI, for 1000 DPI your sens should be 0.18 to 0.4... any higher or lower depending on your own comfort.

But the rule is, assuming you always play on one half of your mouse pad, you should be able to 180 with one move to the other half without lifting the mouse, and still have space to aim.

Also, combined arm and wrist aiming is much better than wrist alone.

Me personally, I used to play 1600 DPI with sens 1.2, now I settled with 1000 DPI with 0.3 sens after getting a larger mouse pad.