Clip on Tuners. They're like the clip on bow tie of the guitar world. They might look stupid. But they work. Really, really well.
Staying in tune is important. Unless being out of tune is like "your thing" or whatever. But for real, you need to be in tune if you're going to play any instrument. It doesn't matter if you're at home by yourself or jamming with your friends. Be in tune, and be that way all of the time. Why? Because being in tune, and tuning constantly will train your ears to know when you're out of tune.
For us guitar players, you can actually train your ears to know exactly what string is out, and if it's flat or sharp. Have you ever seen one of those dudes that can pick a guitar up that's terribly out of tune and within like five seconds they've tuned the guitar by ear, with no tuner. And they didn't do that stupid thing where you hold down the string at the 5th fret and then hit another open string, and then try to match the way they sound blah blah blah...who cares, you look really dumb doing that. Good guitar players can tune by ear just by hearing the sound of open strings. How do they do that you might ask? Well, most of the time it's because they've spent a lot of time tuning. That's how. And let's be honest, they're cooler than you. And me.
Clip on tuners are an inexpensive way to help you stay in tune. Yes they look silly just hanging out up there on your Fender MIM Telecaster headstock but they are extremely convenient. And because you have it there, you can use it constantly. Want to train your ears? Keep your clip on tuner on your guitar, and use it when you need to tune up quickly. But in your down time, turn the tuner on, and DO NOT LOOK AT IT.
Try using your ears to tune your guitar. If you get lost, take a peak at your clip on tuner to find out if you're flat or sharp. And again, tune up constantly. Training your ears this way is a great exercise that will only make you a better musician.
Need a suggestion for a great clip on tuner? Check out the SNARK! These are my favorite. Super easy to use, durable, and usually very accurate. You can get one here for around $12 bucks.
Need a how-to video? Check this out!