I've been making a bunch of arrows. these require arrow heads, staves, and fletching.
For the staves I make crude quality, and i have my tailor friend make crude fletching. This can be done very quickly, and because these synths do not yield multiple items, it makes no difference.
Now, for my alchemist, making pristine quality yields 4 output items from 1 synth, so in that situation, it makes sense to fight for pristine items.
I would say a good rule is in situations where output quality does not determine output number, make the quickest possible sub components. Where quality DOES determine quantity, make the most possible.