/u/altdecay gave you solid advice. I was once advised against aiming for the 'perfect take' but to rather just do 4 or 5 and settle on the best one. This did not turn out to be good advice as I'm very anxious about recording and therefore screw up a lot. If I settled on half the takes I did, I would just be releasing things that are unbearable for most to listen to. I can play live fine for whatever reason, but recording is arduous and painful.
I have caused my fingers to bleed and had to replace some nails with acrylics due to the intensity of aiming for 'the perfect take'.
The mistake I was making was trying to get the 'perfect take' all at once!!! /u/altdecay suggested splicing all the perfect parts of your takes, and THAT was the ultimate solution that saved my sanity, my fingers, and my desire to record music.
I DO have some concerns about looping I would like to discuss with you, however. As a musician, I often hear demos of people who will be playing the same show as me, and it is often looped, which makes me question their ability to play live. I think it is better to have SOME parts out of tempo or to have a little blip where you don't get the bass note right than do have a totally 'perfect' song made of loops. Looping can suck the soul right out of songs, and from what I've been hearing lately it HAS been sucking the soul out of songs.
I use looping when in the appropriate genre (like hip hop or techno). Otherwise, it is better to learn the song on your instrument to the point that it's nearly perfect (always use the metronome) and do the song in one whole in-all-its-glory (naked) take. Do several of the takes and splice the best parts together. Voila, you have a song that sounds good, but does not sound like it is made in a factory. Make sure you do all the takes in one session so that the input levels and the room ambience are the same (otherwise it is obvious frankenstein).