The biggest sounds I've gotten involve several steps
1) Get the guitar and amp sounding just right in the room you will be recording in.
2) Get you mics placed correctly to get the best sound to your recording device.
3) Play at least 2 takes of the same part with the exact same setup.
4) Play around with panning your parts in different ways.
I find that 2 or more mono parts sound better in stereo than 2 stereo parts panned differently, though that can work too. It just gets busy.
If that's not what you are looking for, try changing the EQ, verb, and/or delay for the 3rd and 4th takes and pan them out as well.
The key is to have several different performances. I don't know of any other easy way to get a huge sound without a really nice room, amp, guitar and a forest of mics.
If you are using a DAW, you can "cheat" by pasting Take 1 Verse 2 under Take 1 Verse 1, and pasting Take 1 Verse 1 under Verse 2, etc. Depending on your playing ability, it is usually faster to just play the part again.
In the mixing, as Tex said, "a sense of space" is really important to big guitar sounds. I find that delays are more effective than verbs as verbs tend to wash the sound out and diffuse it unless you use a light touch.
Have fun! Big guitars are always and adventure.
Take care,
Chris