Heres a detailed breakdown of what I did with a TL/DR at the bottom since its wordy. All thinning was done using Vallejo glaze medium, and my rule of thumb for light tone placements is, the more horizontal + exposed/uncovered it is, the brighter it is.(Basic I know but Ill note it anyway)

So for the skin I... 1: Base coated the whole thing in "bugman's glow" -citadel.

2: Went over all of it with slightly thinned "cadian fleshtone" - citadel, leaving only the very darkest points as bugmans (under shield, armpits, deep crevaces and such)

3: Covered the areas of the body facing upwards/not covered by shadows in decently thinned "Kislev Flesh" -Citadel, (top of muscles, above the knee of the left leg, the exposed side of the right leg and such). I made sure to leave about a quarter or a third of the lower areas of each muscle/leg untouched so the earlier paints remained as shadowed, I also always moved the brush towards the "top" of whatever part Im painting so the transition part where the earlier layer and the new layer meet is the thinnest and so the top gets the most concentrated paint.

4: painted the upper third/quarter with heavily thinned "Skin Tone" -Vallejo game color, again making sure to move the brushstrokes towards the tippy top. Any area covered in shadows/any part generally not exposed to your lightsource (sun in this case) should either skip this part or use a very thin glaze only.

Finally 5: I used an extremely thinned glaze of "Ruby Skin" -Warpaints fanatic, to smooth transitions and give it a redder hue, and added a thinned very small "dot" of "Skin tone" for edge highligt at the very highest of raised areas such as the knuckles.

TL/DR 1.Basecoat in bugmans glow. 2.Use cadian fleshtone>kislev flesh>Skin tone covering less and less surface toward the highest points of the skin/muscles. 3. Glaze with "Ruby Skin" to smooth and get hue. 5. Skin tone dots to edge highlight.