I've been through a Dashboard Confessional phase before, so I'm familiar with the type of sound you are looking for. Here are some suggestions to try out:
Guitar:Overdub guitar tracks twice, at least the rhythm guitar, and pan them L/R about 50%. Wide enough to not conflict, but not a huge spread. They need to sort of feel like the same guitar, only provide a stereo image so that the listener does not get bored out of their f***ing minds.
Also, I believe that in many of Chris's recordings, the guitar track (each guitar track) is a mix of mic'ed sound and piezo pickup sound. It gives a kind of crispness to the guitar track, but too much and it sounds shitty and amateur. I've had fair success combining piezo/mic sources. Just make that once you think you have the piezo just right, drop it a decibel or three.
Vocals: As someone pointed out, make these fairly clear and upfront.
Other than that, don't use much reverb (for a DC sound).
Oh, and by setting the rhythm guitar tracks at about 50L and 50R, you can use the "outside" of the soundscape for secondary guitar tracks, strings (with stereo reverb), and vocal harmonies.
Hope that helps. And I'd like to hear some of what you get done.
R