While most guitar players look forward to their solo, veteran studio pros will tell you that the rhythm guitar part, which is heard through the entire song, is the glue that holds everything else together. It also tends to be the part that sets the mood for the piece. With that in mind, and since almost all computer-based DAWs, as well as many hardware recorders, have plenty of tracks these days, it pays to either double track a rhythm guitar track or for a fast "thickener," use two different microphones on your rhythm guitar (or guitar amp) with one panned left and one panned right. This done, you can slightly slide one of the two tracks in time so they are not perfectly synched. Even offsets of just a few milliseconds are enough so that the listener's ears hear two distinct tracks. Larger numbers tend to produce a wider stereo stage, and at long times, a panned delay effect. You can also EQ each part separately so that it doesn't sound like the same guitar playing both parts. Or you can keep one side clean and use effects on the other. This is a quick and easy trick that can add depth and character to your rhythm guitar part. Note: Works just fine on other sounds, such as keyboard parts and backing vocals, too.