Dearth of tutorials re Non- destructive Dodging and Burning

[Jaffa]

I say, dearth, because if you google, there is not much mid-range.  I have gone to some of the very good, tried and true, video tutorials, but am disappointed.  James Ritson's "old" tutorial seems to do everything on one layer (it is not clear, because the layers are not shown).  Affinity Revolution is somewhat similar.  I have older material, but when I do as instructed and add a 50% grey layer, with a Blend Mode of "Overlay", then choose, say, mid-tones, opacity 100%, flow 14% and Hardness 19%,  can see no results.  

There are quite a few more advanced tutorials, about using gradients and curves, but since I have trouble at the moment with basics, this becomes somewhat academic.  Any suggested tutorials?

[Max P]

HI

it's OK just  select a brush with little more Black, for this go to Swatches, Grey palette by example 65 % (65-50=> +15 )

If you want see before the effect it's possible fill begin withe an  another Grey the pixel layer Overlay as 70% , or 40%  and after return to 50 % grey

For restrict to the midtones use the blend option

https://forum.affinity.serif.com/uploads/monthly_2019_11/image.png.220baac63e15d6518b06f1865341adf1.png