I found this quite interesting tutorial for the beginners using the Vallejo Game Color Set which I think I can recommend if you are using (or plan to use) this set of paints (like me): If happen you know more of the tutorials using Vallejo (or maybe other vendor) feel free to paste it here! I certainly will update this section with new findings on the road! I personally like the Vallejo set, because I find them to be easier to use than Citadel ones and I happened to be on a live workshop with them and fell in love