Hi
bb09, when I used to be relaxed, the way I'd moisturize my new growth was the same way one applies products to scalp: part a small section, use my finger to either scoop or dip into product and then smooth it on (In this case, from base to end of growth; you might have to rub thumb and first two fingers together and have the hair held between the two to apply to both sides of narrow section. Section should be so narrow that your fingers and thumb are practically touching. I don't think there's any way to get it wrong if you just apply enough to ensure hair has product on it. If you apply too much, you'll still have product on your fingers so you won't need to dip again but can part the next section and apply again. One minute hair isn't shine, the other it is.
Put another way, when you apply serum to fingers and smooth into the narrow section of the hair, you can apply on another narrow section if you still have some left in fingers and you probably can return to first section to get some of the extra. You should apply and fingers be left w/o so you know you need to get more for next section.
Hopefully someone else can break it down better than I can, but I'm not sure I get where the disconnect is.