How do I set nudge distance in Illustrator?

You can change your nudge increments distance in the Preferences Panel(Keyboard increments).

Setting nudge distance/keyboard increment

1. Uncheck snap to pixel in the view tab
2. Change the keyboard increment in the Edit tab ->preference from 1 pixel(by fault) to a tiny one which you want.
3. Tip also: the super nudge is a 10-times shift by holding the shift when using the arrow key.