Here is my technique for recording one guitar and obtaining a stereo spread used in all of the FX Recipe videos. You can apply this technique using a DI and 1 microphone or 2 microphones. A delay plugin and a phase plugin is used to create a stereo field. The phase plugin sets the phase of the left and right channels of the room mic opposite of each other (inverse). When this is mixed with the close mic, it changes the waveform of the left and right channels and creates a stereo effect (even before stereo processing the close mic with delays.). The phase processing it what really helps this mix fold into mono really well.
To change it up a little, I used a preamp based on on a high gain Engl amp that never gets used in the FX Recipe videos.
The riff I use in the recording is based on a King's X song.