every printer is different, so you should work out the tolerance to insert between the parts.
simplest way:
>print a small part (a cylinder) of a certain diameter
>another part with couple holes gradually increasing in diameter by lets say 0.1 mm
>find the hole that has the desired type of fit (for my printer 0.3mm results in a tight fit)
>edit your actal part and ensure there is a gap of this size between the parts
if you are worried about printing a whole useless part, you can just print the piece that matters to the fit by itself. Its normal to do several bad prints before arriving at a part that fits well