I've been preaching this to my students, but I realize that I haven't yet written about it: recording yourself! Nowadays it has become so easy to do that, and I can promise you that it is a valuable tool that helps you to become a better player!
But let's go slow; so why should you record yourself at all?
There are many reasons. I'll try to convince you giving you the ones I find most important:
If you play or practice by yourself you need to focus on a lot of things (what is my right hand doing? what is my left hand doing? how do I sound? how is my timing? etc.), but you can't listen as carefully as you can when you lean back and listen to a recording. Listening to a recording of yourself can be very confronting: suddenly you hear that annoying string that keeps on ringing after that bend; or you hear that your chords are always slightly before the beat, which may sound a bit hectic; maybe it turns out that you're not locked in with the drums at all; is the sound right for the song? You see, there are so many things that are important and that you often can't really judge well while playing.
When listening to their recorded solos, many players realize that they keep on repeating the same phrases over and over again; that their timing isn't the way they thought it was; or that their solo could really need more pauses to make it more interesting.
A similar thing is true for rhythm playing. Experienced players feel when they're locked in with drums and bass, but even they might be wrong sometimes and find out that they want to do the take one more time after listening back to the recording.
The bad news is that for most players, recording themselves will reveal shortcomings of their technique, their timing, etc. The good news is, now you know about it and you can finally do something about it. And hey, after all that's the only way to improve!
I hope that by now you agree that recording yourself does have advantages. Of course it's much more fun (and also more helpful) to be able to make a backing track over which you can try your licks or your rhythm vamps. Or there is that terribly difficult break that you've been trying to play with your band, but there's always someone losing the beat. In the latter case you can just program and/or record that break and practice it at home. And at the next rehearsal you'll be fine, and you can even tell who's the one that needs your backing track to practice at home!
What you need to do all that is a computer, one of the many commercial or free/open DAW software packages, and an audio interface. Simple USB audio interfaces with one or two inputs have become quite cheap, and most of them come with a limited version of some commercial DAW software. So if you have a computer, it is enough to buy a simple audio interface (including the software), and you can start recording and making your own backing tracks.
Apart from becoming a better player (we all want that, don't we?), recording yourself also has a great advantage in finding a band, or finding jobs as a musician. You can present yourself on the internet and people can check you out. If you make some youtube videos, it's easy to get in touch with other players around the world, and often this is the way new projects start. If you don't want to film yourself (think about why), you can still upload audio files on soundcloud to present yourself and get in touch with others.
Finally, if you've reached a certain level, you can also earn money if you're able to produce high-quality recordings at home. And you don't need a lot of expensive equipment for that. When other people ask me to play some guitar tracks on their songs, more often than actually going to a studio, I'd have them send me a recording of the song, I'd record some guitar tracks at home, and send my tracks back so they can put them in their mix.
Enough said, get yourself a USB audio interface with some DAW software and ... start recording!