I will not discuss the different techniques of arranging and composing here, so if you want to know something about good voice-leading, parallel fifths, close voicings or stuff like this I recommend to study a book about composing and arranging. I just want to share my very own method to create harmonies and I will focus on the recording and mixing-aspects.
When I started to compose and record my own songs alone I was confronted with the realisation of many choir-sections. Over the years I tried different methods and ended up with multi-tracking my own voice up to four times. Experiments with artificial generators failed, so even if you generate different voices in a sophisticated pitch-shifter like Melodyne the result will fall short compared to real singing and recording. So don’t waste your time with programming if you are after a natural result.
The big advantage of a male voice is the ability to sing in two very different voices: The usual chest-voice and the seldomly used falsetto-voice. And even if you hate this childish and feminine sound of your muscle-packed body, don’t ignore it, because when it comes to harmony-recording the hated falsetto-voice becomes a treasuer-chest, even for the tattooed Hard-rocker.
The first and obvious advantage of the falsetto is the extended range for your voice. Usually you will hit higher notes with less effort of your voice. The second advantage is, that your multitracked choir is not just sounding like you times four. It will sound like a mixed choir of more than one person, probably like two male and two female singers, for sure it will sound like “more than one” singer. It will sound similar to some bands of the seventies, which worked with multitracked choirs like QUEEN, YES, or 10CC.
So my choirs always contain falsetto, mostly the two highest voices are sung with falsetto, the two lower voices with the chest-voice. Depending on the range of the whole vocal-arrangement I also change sometimes within one voice between chest-voice and falsetto, if the top-notes are too high or I would have to sing them with much effort. If you sing with effort the resulting voice will sound too harsh and aggressive and it will be hard to integrate it in the mix. Better try to sing all voices relaxed.
Avoid to apply wide vibrato, fast dynamic changes and other exaggerated expressions, because a choir should sound like a disciplined ensemble and not like four individuals. Every dynamics and expressions should be mirrored by all four voices to keep the ensemble-sound tight and focused.
For the recording I made good experiences with small condensers like the AKG C-1000S. Extended bass-range is not necessary for choir, better to have clear highs.
At the end you have recorded all voices. Afterwards I highly recommend intonation-correction, if necessary. While some intonation-issues of the lead singer are mostly not critical, everybody will recognise, when your choir is out of tune. So listen very critically and don’t hesitate to use Melodyne or something else for post-editing.
At last some mixing advices: The highest voice tend to stand out, especially if it’s octave-doubled. Therefore it’s better to lower the volume and not to place it hard left or right, where it will stand out more. Usually I place the highest and the deepest voice somewhere around Pan -20 to +20, while the two middle voices are placed around -45 and +45 left and right. Often the middle-voices need more support than the lead-voice. Within a mix the choir is placed in the background, so it will get more reverb and less highs than the main singer. To separate the choir from the other instruments it works best for me to cut the lows extremely up to around 200hz or more and eventually raise the highs a bit to support the articulation of the lyrics.
This is an example how it can sound at last. There is also a section, where you can hear a falsetto-voice alone.