It looks like you have the theory down. But your paint looks very thick, resulting in very harsh transitions between layers. Try this with thinner paint. Assuming you are using acrylic paint, water will work nicely for thinning. Be careful to not overload your brush with paint and - working with lighter colors - pull the brush from the shadow towards the highlight. Let dry and repeat or move to the next color. With some practice you can get very smooth transitions this way.
Working with darker colors is pretty much the same, only you push the paint from highlight to shadow.
For a consistent result also try to apply the same theory to all areas (metallics). This doesn't mean everything needs the same number of layers though.
That being said, if you never worked with diluted paint before, forget about more or less complex shading and highlighting for now and just practice working with thinned paint as it can take some getting used to.
And keep posting your progress :)
