How do I go nil without lag?

If I put my player in nil, it lags alot, how do I do this without lagging?

First explane how it lags and what kind of nil you are on...

Second, if it is a brick CFraming WITHOUT a while true do loop then message me. I have made my own nil probe before.

If all you are doing is changing the Parent property of your player to nil, then there should be no lag. Any lag caused by only reparenting is to be blamed on ROBLOX or some other script. If you are doing something else, like spawning parts in, please state what you are doing, and I will change my answer to describe how to fix it.