What tool do you use for doing this? Just a small metric ruler or somthing else?
Also, when I see people referencing their string heights here, I assume they are measuring the space from the bottom of the string to the the top of the fingerboard. Is this correct?
You can use a small allen wrench as a feeler guage. just find the size you want (2mm,etc.). put a flat side against the top of last fret, and it should barely touch the bottom of the string. You can use different ones for different hieght.
Owner/The Bass Spa, String Repairman/L & M Vancouver
Join Date: May 2006
Location: Crescent Beach, BC
Steve, a small metric ruler works very well to measure from the bottom of the string to the top of the board at the end.
Holding down each string at the nut and at the end of the board will give you a straight reference line to see how much camber or "scoop" there is in your fingerboard under the different strings. In a perfect world there should be more camber under the E than under the A, than under the D, etc
The two values work hand in hand in allowing for string excursion and ease of playing.
Last Fret? Is this a Viol d'Gamba or a mistake in posting?
On a DB, most people just use a ruler and measure just like you said, "measuring the space from the bottom of the string to the the top of the fingerboard" (not Fretboard!).
The average I see is 5-6mm on the 'G' (I have gone to 4mm or less sometimes) and going progressively higher for each string about 1-1.5mm. There is no exact measurement as a standard. Half the Fingerboards on Basses need replacing to match the easier altered Bridge arch.
When having a new Fingerboard put on the Bass, make sure the Luthier knows what your preference is for Bridge height so he can do a good match with the fingerboard radius.
Nut height is also important and I like mine close to unmeasurable at the end of the FB with about a 1mm scoop from the Nut to the butt of the Neck and fairly flat from there to the end of the FB. Spacing for me averages from 10mm to 11mm centered depending on the width of the neck. For Bridge spacing I now prefer 27mm or 1.1" again depending on the tapered width of the fingerboard so I have just the right amount of overhang of ebony outside the strings at both ends.
top of last Fret? 
