I desired to produce this album as well. This is a big undertaking, yet well worth it!
First of all, I wrote out the charts for each song. I usually write them out in Nashville Number System, often with chords provided instead, since there are musicians who are more comfortable with chords. In this process of several drafts, I am determining the best possible intro, coda/outro, instrumental and tempo.
Secondly, it is important to 'breathe' a song. Wha? To create depth in a song, or as I call it (give it 'breath'), it is good to provide dynamics and breakdowns.
Dynamics is directing the musicians to play soft, medium, loud, along with places where to hold chords for a measure, or rather to STOP immediately. This gives expression and excitement to the ears and emotional reactivity to the listeners ears.
A breakdown, is where, several instruments drop out, leaving perhaps just a basic beat of a snare drum with a guitar alone, for 4-8 measures, which may bring emphasis to the vocal passage. This effect can give the song anticipation and interest in general.
Once the charts are written out, I play them over and over again, weeding out bloopers (mistakes), that save time and money in the studio. No matter how meticulous I am about this process, it seems a pesky blooper get past me. Lol. Meanwhile, I check and recheck the tempo. On studio day, with all the musicians playing and thus reshaping the feeling of the song, the tempo often will change a couple clicks slower or faster. If I give a starting point for tempo, again, I save time and money.
Once the charts are written, I focus my creative imagination on what instruments would be best for each song. This album's genre is Country. So I already know that there is acoustic and electric guitar; lead guitar which also can be slide guitar; dobro; mandolin; banjo; fiddle; keys which include piano, electric piano, string effects; 'wurly' (wurlitzer); accordion; flute, etc.
So each of the twelve songs has a personality, that will lend itself to different instrumentation. What helps me 'hear' the particular instruments for each song, is this: while driving here and there, I play the demo'd songs in my Subaru. I also add the songs to my i-Tunes and listen to them while droning out on the elliptical. I then ask myself, "What is the best instruments for this song?" Then I somehow, little by little I start 'hearing' with an inner ear, what imaginary instruments are filling in, behind the guitar/vocal demo's.
Then once I know who the 'players' are (what instruments are for each song), I will determine exactly where each instrument fills in here and there. If there is a melodic theme, what instrument will play it. On the first verse, perhaps I'll have the piano 'decorate' the end of the phrases, while on the second verse, I'll have the dobro decorate the end of the phrases. Then perhaps on the chorus, I'll have the lead guitar decorate, as well as take the solo. On my charts, I will colour code where each particular instrument plays and/or decorates. By the way, when I say 'decorate', it refers to the end of a the singer's phrase, where there's a space for an instrument to 'decorate'. The instrument says something interesting before the singer begins with another phrase of lyrics.
I will colour code each particular instrument, so as the producer/director, i can quickly look at my copy of the song chart and see what instrument is supposed to be playing when and where. Each musician will also be able to see exactly where and when to play, with the colour codes. There's no guess work, which also allows the musicians to feel at ease.
When I, as the producer, provide the musicians with an orderly chart and game plan, this gives the musicians the freedom to play and create to their best ability for each song. This is a win-win for the musicians, singer(s), engineer and producer. The more I prepare beforehand, the smoother the studio day(s) go. There may be some unpredictable situations that come up, be it technical, etc. Yet, with the game plan well prepared, it allows time and patience for those ordeals to unravel.