All good suggestions. Just remember to treat the face like any other "fabric" on the mini. And that LoTR models are smaller than the standard GW models. So looking at tutorials they'll have to be slightly scaled down in your head. Sometimes steps have to be ignored or altered.
-Block in the skin in the basecoat/skintone of your desire
-Do a midtone highlight
-Do a hightone highlight
Some take the basecoat and mix a lighter color in to get the transitions as opposed to actually getting a new paint. As in: Dwarf basecoat, Bronze midlayer, Elf final layer, most will take the Dwarf flesh and mix in bleach bone to get the transition of the paint to their desire. Depending on what you are after you might even add a dark color to the basecoat (Choas Black and Dwarf) and then use the original basecoat (Dwarf flesh) as your midtone/layer and then add in Bleach Bone to the original basecoat (Dwarf flesh) as a final highlight.
As to the eyes. I've noticed that most GW LoTR models have noticeable protruding eyelids, gives them a squinting look, that will catch the brush before the brush can contact the iris of the eye. Resulting in the "Gollum" look. What I suggest is take a .005Micron pen and do a dark slash and leave it at that. Or use a 5/0 or a 00 (depending on the brand) brush and do the same with black paint. If you have your heart set on making eyes, then do a slash in ...white...(you'd have to use a brush) and then for the pupil do a vertical slash from eyebrow to lower eyelid...then repaint the face/skin where the vertical slash is. A trick to doing the eyes is to do one side that is easiest/comfortable for you (depending on which is your dominate hand) and then flip and rotate the model to do the opposite eye. The model will be "upside-down." Then take a water down purple wash and lightly apply it to the lower part of the lower eyelid and streak it to and down 1/2 the nose. Gives it a warm shade and bolsters the eyes.
Lastly 2 things...most mini's are observed from a arms length away. If it looks good viewed from your outstretched arm, kudo's!!
and lastly: practice-practice-practice. Use a mini that you can practice on constantly (practice-strip-rinse-repeat-) and it'll become 2nd-nature. I have a Rohirrim model that I don't even prime...I just base and go from there.
Hope that helps at least a little -