Now lets address the lead guitar. First and foremost, I like to use a different amp sound to contrast the rhythm guitars. Since we want the lead to sit on top of the mix to show off our hot licks, I choose a midrange heavy amp and use the equalizer to remove unneccesary frequencies(just like we did with the rhythm tracks). You'll notice I also take more bass out in the EQ to help the lead find its own spot in our mix.
Once the guitar sounds like it fits in cleanly, I'll add compression to really squeeze down the dynamics and make every note of the solo audible. The amount of compression I use varies depending on the tone and feel of the lead.
I also like to add in a nice subtle delay to the lead to give it a slightly bigger sound, but that is entirely personal preference.