This is what I do...
a) I record the rhythm guitar first...that gives me my beat/ tempo etc. I record
acoustic guitar based songs
b) I might add the vocal next, if the song has a vocal
c) I start to record licks, second guitar parts like melody, fills etc
d) I start to think about percussion...this is limited to tapping away on a snare, shaking shakers or banging something like a tambourine. I don't do full on drums
e) Do some vocal harmonies if I can think of any
f) Start thinking about effects and colourings for any part of the sound...if I haven't already started to do that before
g) Listen to it over and over, ironing out problems, tweaking things, clearing excess sections of takes with nothing on them
h) Do a mixdown, open the mixed file in Wavelab and usually apply denoise, declick, stereo expander, and I might mess with the multi band eq to take away some boom
That's pretty much it...maybe not always in that order...but step 1 is always the same. So, to answer that question, yeah, I personally like to have the whole song played out...as opposed to doing the intro first and then building it like that. My acoustic base lays out the entire song. That's always step 1...so obviously there are a fair few takes and aborted takes etc. That's the hard part. Once I have that entire base, the fun parts begin I reckon. I did 'Julia' by John Lennon once, and getting the whole finger picked song in one take took me ages. Funnily enough, after that, I was pretty much done because it's just basically one guitar and a couple of vocals.