Had some heart issues last week but am doing fine now except for a heart rate hovering around 50 that I see my Doc for today to get a medication reduction. I only weigh 145 lbs, exactly what I weighed when I barely graduated from high school because I majored in parking lot....
So I thought I would make a post worthy of saving for those who love setting up guitars or even just have to set-up their own creations. If you are commercial and make money doing this these specs are what I use to set-up around 600 guitars annually and the satisfaction level is very high.
I'm a numbers guy, addicted to data and science and that's my North Star in guitar set-ups. I've also set them up for some very famous players and they tour with my set-ups.
As you may have noticed I'm a stickler for providing attribution too so some of this is previously published to Martin service center specs, some is Fender, some is my own and much of it is from Dave Collins who I apprenticed for for three years and have been with now in business for close to 17 years.
For the last year I've worked nights by choice to avoid people because of my health and even more my 90 year old Mom in assisted living. Hesh here does NOT want to be the one to bring covid into an assisted living facility... As such I do not have the benefit at present of speaking with or observing how a client plays before I set-up their ax. This means that my set-ups have to be rather generic and one size trying to fit all. With this said these specs that you will find below have to work and they have to work the vast majority of the time for people and they do exactly that.
My return for minor adjustment rate is less than .5% so I think this is pretty reliable stuff. Not saying that a specific player may not need a minor tweak or that some folks require custom set-ups, they certainly do. But for the generic player these will serve you very well as they have made us a lot of money and earned hundreds of five star reviews. The proof is in the results.
Acoustics:
Traditional D, OM, OOO and all Martinesque traditionally built acoustic guitars with 13's high e at the 12th 4.5/64th" and low e also at the 12th 6.5/64th." A heavy handed flat picking blue grasser benefits from 5/64th" and 7/64th."
We always measure action at the 12th and Dave and I use a combination of fractions and decimals to quantify because it works for us. We always indicate the treble string specs first and then the bass string.
With 12's - 4/64th" and 6/64" for a blue grassing or generic D size flat picker.
for finger style players with 13's 4 (64th) and <6 and now I am going to call it simply 4 and <6.
for finger style players with 12's 4 and 5.5 a tad lower than with 13's
12 strings 3.5 - 4 and the fret work needs to be decent. 12's are already hard to play so it's very important to lower that action and a quality fret plane is required. Some rattling on a 12 is acceptable and audible on the most famous recording of our 60's heroes, well mine any way...

Electrics
10's - 4 - 4.2 to 4.5
11's - 4 - 4.5 or a tad less, more massive strings lash out less because they have more inertial to overcome which was very counter intuitive to me when I started and is old hat now.
9's - 4 - 4.5 and at times a tad higher again because 9's lash out more than 10's with LESS inertia to overcome.
12's - 4 and near 4 if the player is not a heavy hitter.
Now with my fret work I can go lower on any of these situations but better players are not fans most of the time of uber low action nor am I. We want to be able to get under a string for bends and vibrato deep in a bend and we want the option of digging in and trying for that angelic note that rings and sings sweetly with emphasis when appropriate and in my case even when not.

There is a phenomena in guitar set-ups these days with the shredders who often like 9's, very low action, and they may tune down to C...... so for them: They like Ibanez guitars too with Floyds.
Tell them that their guitar is going to rattle if they hit hard and that's to be expected and if that's an issue take it elsewhere we set expectations accurately in advance. Conventional 5 string guitars were never intended to be tuned to C. We do it all of the time but it requires a customer set-up as below.
This also includes 7 strings with an even lower bass string. There may not be enough travel in the B string saddle to intonate exactly for C either.
9's 4/5-6 again for people tuned to low C.....
10's 4/ 5-6 low C again
Bass
long scale 5/7
short scale 4.5/6
five string with a B set the B at 7 and the low E at 6 transitioning to the g at 5ish or a tad lower.
Mandolin
3/3.5
So there are some dependancies here that will force us to raise action and all of these numbers presuppose that the truss rod is properly set, we like a very flat neck with minimal relief on the treble side and a bit more on the bass side. This is not always available either so we may do a work around.
Nut slots have to be cut with great skill very low but never buzzing on an open string.
For us, for me it's:
Before starting always, always tune to pitch to set the exact tension of the strings. This means whatever pitch means for this client incase they do drop tuning or alternate tunings.
For alternate tuning players I set-up for the tunings that they use MOST of the time.
1). Adjust the truss rod
2). cut the nut slots
3). adjust action at the 12th with the saddle(s)
4). go home
Please note that many guitars, many have bad necks and crappy fret work. Then these specs may not be achievable until the fret issues are resolved and if that's not possible we set higher. Many Fender style guitars with bolt on necks have ski ramps on the fret retention over the body. This forces us to set the high e, b, g higher than most people may like unless again "fall-away" is milled and it has a quality, proper fret dress first.
Now I just gave it up, the holy grail and I believe the most useful post I have ever made here on the OLF and with my multiple IDs I'm now well over 30,000 posts.
So my hope is that this will serve you very well for a long time and make many people happy with very well set-up guitars. I also hope that people will fall in love with your guitars because when they try them they play like butter and play better than any other guitar the prospect has or has played.
People are thrilled with our results and tell us so nearly every day and this has been the most rewarding thing I have ever personally done and made more people happy than I can count. I love what I do and plan on doing until I can't.
Lastly we have just over 1,000 square feet of commercial guitar repair shop in the epicenter of Ann Arbor. We have several rooms including a tool room in a 120 year old historic building in the center of town. Here is a shot of my bench, a small corner of our world but where most of our revenue is generated. Around 60% of our revenue is from set-ups and that's what I mostly do with some bridge reglues, fret work, crack repair, pup instals, tuner replacement, unslotted pin conversions and lots of other stuff etc. With my hernias these days Dave does the neck resets since you have to get on the floor and wrestle with the things....

. Kidding of course. Nothing to get steamed about...
Point being to do great set-ups you don't need much beyond a nice work space, good lighting, an engineer's scale to measure with, a belt sander and the knowledge to make it happen. You do not need a professional guitar shop to set-up an instrument superbly. There is no reason why you can't do this at home as well or better than this old dude.
And really lastly and this has been a repeated point from me over the years and this time thanks to a friend here I am going to be sure to try to have a more friendly, less judgmental tone

. Hesh may be a lot of things and some are not good but I am trainable.... and I do "hear" people. Many of us like me come to the OLF wanting to learn about the woodworking of building a guitar. Along the way we learn that ultimately as our project approaches completion it's no longer a woodworking project but a soon to be "tool for a musician." This means it has to play great and you have to know how to set it up to play great. That's why I am posting this today, your final steps if you don't know this stuff or your methods have you back tracking with issues at times. I never have to back track. Once I cut nut slots there is no reason to change it, ever. Once I set the rod same deal, I get to move on. Just be sure to tune to pitch, the player's preferred tuning pitch.
Hope this helps and of course if you have any questions let's help you out!
PS: The pic overlooking me and my work is Sammy Davis joking around with Mohammad Ali and makes me smile seeing it every day.