I've always had trouble tuning my guitar without a tuner, I try to sing a high E but end up on either C or D. Though when i hear the note E i can repeat it.
You don't have absolute pitch. Nor do too many people. You can train your ears, but it could take years. Every time you walk past the guitar, sing that E before you play it. The guitar shouldn't be much out of tune, anyway. If it is, there's something awry with it, or where it's kept. Or ban the kids from being near it.
Stick with a tuner, or maybe better, if you don't need to be in tune with concert pitch, tune it all referencing the bottom string. Your ears will benefit, as will your sense of intervals.
Being able to identify and/or reproduce a pitch without any reference is called absolute pitch. It's a rare ability that is not necessarily all that useful. It can even be considered harmful because people with absolute pitch are said to have difficulties with alternate tunings and transpositions.
Most musicians don't have it. What most do have, though, is relative pitch. It is the ability to identify and/or reproduce a pitch given a reference. Like when someone gives you an A and you are able to sing an E.
Even if you had have absolute pitch, it would have probably not been the best way to tune your instrument anyway. Studies show that the accuracy of people with absolute pitch is not perfect.
So my advice is to go back to using a tuner or a tuning fork like the rest of us :)
From the comments it seems that you're tuning the strings in sequence from hi to low one from another.
If it's your own guitar it should stay pretty close unless you're travelling with it or introducing other environmental changes. So you can check over all the strings and tune outward from wherever the stable nucleus is.
I have some details on tuning from one external note but the important point of always tuning up leads to two kinds of checking one string from another:
scoop tuning the lower note of a tempered fourth should be slightly flatter than the perfect fourth.
nudge tuning the upper note of a tempered fourth should be slightly sharper than the perfect fourth.
So, if you tune it up from a known external high e, then:
- scoop the b so it's on the underside of the perfect fourth below the e.
- unison the 5th-fret harmonic on the low E with the high e.
- nudge the A so it's on the upperside of the perfect fourth above the E.
- nudge the D so it's on the upperside of the perfect fourth above the A.
- nudge the G so it's on the upperside of the perfect fourth above the G.
- check the G-B is a nice major third
- check E-B-G and G-B-D triads
If you always tune up, then the gears in the tuning machine are locked. If you go too far, always detune and try again from below. The guitar should mostly stay in tune from day to day.
I also use @Nae's technique of using a song either from a recording or memory.
TL;DR This is absolutely possible to train, and it's called pitch memory. Most people in this thread are under the misconception that this skill is a) useless and b) requires "perfect pitch" or "absolute pitch".
Pitch memory is exactly what it sounds like, if you think of a sound that is well stored in your memory, it comes out at the correct pitch. It's difficult to not let surrounding sounds make you accidentally transpose your own memory, but it's possible.
Personally, whenever I tune a guitar with no reference. I use two sources, and check they are concordant. I use a 440hz sine wave tone I have memorised, and I check it against some popular songs.
The reason I have this sine wave memorised is because I haven't used a guitar tuner (except perhaps when more than a little inebriated) in years. I always tune to a reference pitch. Usually I use this video, And before than I used to use the button on the micro cube that produces an a440 tone. After many years of using it, it's been lodged in my brain.
I once knew a guitar teacher who told me said he set his alarm clock to a440 for 6 months and eventually he could sing it at will. That might be a bit much, but it worked for him!!!
However, usually popular songs are easier than just tones, because they're more memorable. When you have something stuck in your head, or are humming it a lot, it tends to lodge in. If you're a piano player, and you have a particular study you have played a million times, chances are, when you think of it, it comes out at the right pitch too.
I've found acoustic songs in G (like Green day - time of your life for example) which have a strong intro work well. Similarly, sweet home Alabama, the chain by fleetwood mac, and more recently the intro to uptown funk all are lodged in my memory at the exact pitch. You can probably think of a few songs that are too.
You want to pick a song with a strong intro, which you know very well, and preferably is in an easy key to tune from (so E A D G B of course, but also C because you can tune a G to a C easily, perfect fifths are as easy as octaves to tune to) Stevie wonder's Superstition is great in terms of its memorability factor, but unless you're tuning to e flat, you then have to mentally move a semitone up, which is a pain. It's a little easier to focus on the memory of a song and tune to that, than to focus on the memory of a song, hum the tonic, and then move it up a semitone, especially in a noisy room.
After a quick google, I've found there are a bunch of tools online to train pitch memory too. I've never used them so I can't vouch for them, but I imagine they're probably good.
For some reason, the comments of this thread have been focussed much more on trying to persuade you not to bother than to help you how to do it. So for the sake of argument, why might you want to do this?
You're around a campfire on a beach and someone hands you a battered, carried on someone's back guitar. It's not that important to get it up to true pitch, but you don't want to be too far out, because it can take the oomph out of some songs if you're flat by too much, and snap a string if you're too sharp.
Round a friend or something more's place, and they have an "I always meant to learn but never did" guitar.
Someone hands you a guitar, and you want to be able to do a quick internal check of what pitch its at without breaking out your phone.
You're somewhere with no internet connection and no tuner.
Some people are saying there isn't really a single "standard E tuning" that is "common for most guitars", because there are different standards for 'concert pitch'***
While technically correct, in almost all situations there is. A=440. Unless you're playing with an orchestra (who are usually just a smidgeon sharper than 440 such that it doesn't even matter), playing period correct baroque or renaissance music, or playing with someone who for some reason is convinced a440 is from the nazis and we should all play at 432 (yes, they exist) then A=440Hz.
Again, this ability is completely separate from absolute pitch, also known as perfect pitch. However, before learning this you should already have very good relative pitch, that is to say, you should be able to, given any note, sing any other note. If you hear a C, and I ask for the A flat above it, you should be able to mentally jump up a fifth plus a semitone, and then sing the A flat. If you can't already do this I would focus on this skill, which is truly invaluable to a musicians, especially anyone improvising or composing, before working on tuning without a tuner, which, while a lot of fun, is more of a party trick.
There are a lot of online ear training resources and videos to train relative pitch which are very good.
Try tuning the A string first.I use Neil Young's Hey Hey My My(Into the Black) as a reference for the open A, then tune all the other strings accordingly.It stays in your head,possibly due to the way the chord rings out and resonates in the beginning of the song.No guarantees it will work for you but it usually gets me right in range of 440.