I saw many groups with great instrumentalists, but singing is something on the sideline. Usually the songwriter takes over the job as a singer, because noone else wants to do it - and this besides his instrument. And that's what it sounds like: a great backing group with an incidental job on the microphone.
What First?I usually record the playback first to get a feeling of the result. It is easy to change the sounds of instruments, specially synthesizer. But you cannot change the sound of your voice. Recording vocals again will be more time-consuming.
Warm UpFor vocals are very important I spent special time to prepare for recording vocals. I try to be in a good mood. To achieve this I take a guitar and just sing one or two of my songs. Later I start singing playback to the computer the song I want to record. I try to find special accentuation and maybe variations of the notes. These rehearsals are important for getting in the right mood and warm up the voice.
Feel AlrightI try not being tired or out of breath or with full stomach after a big dining. No matter what time, midday or 2am, if I feel alright why not record. Microphone should be away from reflective surfaces.
Recording ProcessI usually record the vocals by repeating the vocal part as long I am pleased with the result. When I feel I have the best done I take this recording. Some recording engineers cut out pieces of different recordings and glue it together for the song. But that is too much work.
The more it may happen that the feeling is not right. You may have a version sung full of power but a little out of key and another version sung correctly but too boring. If you combine parts of these recordings it may not fit.
So better singing one time until all is ok. And the often you sing the more you get familiar with the song.
I usually listen to a pre-mix before recording, but while recording I used to hear only
- the vocal notes played
by an organ
- a clock (simple drums or tick)
Some recording engineers do a rough mixdown for the singer's headphones. That can work too.