I always do it without tools. If you fret the fires fret and the last fret and look down at the 12th fret or so, you can judge neck relief without tools. There should be very little gap between the neck and the string. If there is no gap, you may need some relief. Just remember to make small adjustments.
Once you get the neck just right, lower the action as low as you can get it without buzzing or fretting out. Play every note on every string. If it frets out, raise it up a little. It should fret out pretty evenly all overd the board if you got your neck set right. If it buzzes by the first frets, the neck needs relief. If it buzzes only in the middle, the neck may have too much relief. Always make small corrections and give it time to settle and you'll be good to go. Doing it by feel is the best way to set up a guitar so that it feels great every time!