I spent way too much money getting my guitars set up every time I changed tunings, or string gauges. I learned how to do it myself and never looked back, I even set up my friends stuff for pizza/beer lol.
Here's a good article to get you started:
TECH TIP
How to get the best guitar setup
By Dennis Kambury
You finally bought that guitar you've been eyeing for a long time. You open the case, gently remove it from its plush cradle, and hold it in your arms. A fresh pick in your fingers, you begin an elegant and complex arpeggio that ranges across the fretboard. Suddenly, right in the middle of the run, the strings start buzzing. You check your technique and it's fine. So what's the problem?
Rest assured that it's not the quality of your guitar. The problem lies in the process of mass production. Without it, most guitars would not be affordable. To respond to demand and maximize profit, the factories build them and ship them as fast as possible. Very often, the human touch is involved, but setting up a guitar correctly is a painstaking, personal process that is best handled on an individual basis.
Although a complete tutorial is beyond the scope of a tech tip, we'll outline the basics, and give you some recommendations to further your pursuit of the perfect guitar! Caution dictates that if you don't know how to do the things we mention, you take your guitar to a qualified luthier who has the experience and tools to accomplish these tasks quickly and easily. It's relatively inexpensive and well worth it!
Another caution--for any alterations you perform, make them small! Adjust truss rods by no more than a quarter turn, shave saddles or nuts carefully, and always exercise caution.
First Things First
To get results that work for you, you need to assess your style, technique, and preferences, and make sure your guitar is basically prepared for those considerations. For example, if you like low, quick action, you will most likely go for a lighter gauge string set. Conversely, if you are after a meaty, chunky sound, you're a candidate for heavier gauge strings. Before you start, set your guitar up with the string type and gauge you prefer, and make sure it's in tune.
To get your guitar in top playing condition, you need to look at four specific areas: neck bow or relief, string height at the nut, string height at the saddle, and intonation.
Relief
Take a look at your low E-string when you strike it, and note the curvature--how it "bows" in the middle. If you play hard or use lighter, low-tension strings, this bow is more pronounced; and if you play quietly or use higher-tension strings, you'll see a softer curve. If the strings are too close to the fingerboard, the vibrating string will hit the frets and result in buzz. You can solve the problem by raising the action high enough to prevent buzzing, but this can make the guitar difficult to play and increases the likelihood of intonation problems. Another way to avoid the buzz is to introduce a slight curvature to the neck that gives the middle of the string room to vibrate.
To check the relief of your neck, press the string at the first fret and where the neck joins the body. If you find your strings are actually touching the middle of the fingerboard, you're guitar definitely needs some adjustment! However, if the distance midway between the two points is around 1/64th of an inch, you're in the ballpark. If you are a light player you can get away with less. And of course, if you are a hard player, you'll want a little more room for your fiery passages. To adjust the neck, follow the manufacturer's recommendations and adjust the truss rod to compensate. Usually, this means loosening it a bit to increase the relief and bow in the neck, or tightening it to decrease the relief and straighten the neck.
String Height
The next thing you want to do is check the height of the un-fretted strings above the frets. At the first fret and at the 12th fret of the first and sixth strings, measure the distance from the top of the fret and the bottom of the string. As with relief, there is some room here for personal preference, but here are some general guidelines:
1st fret - 1/64th of an inch at the first string and 1/32nd of an inch on the sixth string. This is good for both electric and acoustic guitars.
12th fret - 5/64th of an inch at the first string and 7/64th of an inch on the sixth string. These dimensions are good for acoustic guitars. For electric guitars, the first string is 3/64th of an inch and the sixth string is 5/64th of an inch.
If your string height is much higher or lower, you'll need to make some adjustments. The easiest place to start is the saddle. Most electric guitars have either thumbwheels or set-screws that make it easy to raise or lower the strings. To determine how much to raise or lower, a good rule of thumb is that it will take twice the correction at the saddle as the amount that needs to be corrected at the 12th fret. For example, if you want the sixth string to be 5/64th of an inch and it's 7/64th, you'll need to lower the string by 1/16th inch at the saddle.
Acoustic guitar is a bit more involved, as the saddle will have to be removed and either carefully shaved to lower the strings or shimmed to raise them. When shaving a saddle, use a flat file and make absolutely sure the bottom stays flat to prevent the saddle from rocking in its cradle!
You can also trim the nut but that takes specialized tools and, unless you're already proficient in this area, we recommend the services of a pro.
Intonation
To check the intonation, play each string at the 12th fret, and compare it to the natural octave harmonic at the same location. If the fretted note is higher than the harmonic, adjust the saddle toward the tailpiece of the guitar to lengthen the string. Conversely, if the fretted note is lower than the harmonic, move the saddle toward the neck. Some bridges allow you to adjust each string independently, which makes it easy to get perfect intonation. Otherwise, you'll have to settle on a compromise that works for your particular style.
Acoustic guitars are more demanding, requiring that saddle itself be cut to adjust each string's break point, and should be done by a pro.
Conclusion
Setting up your guitar properly will make it sound better, make it easier to play, and could possibly improve your playing! If you take your time and work deliberately, you should have no trouble making basic adjustments and keeping your guitar in top playing condition.