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There are alot of techniques to shading. My recomendation for you would be to do this.
1. buy some inks, see how you like the effects inks give you, they are the quickest way to produce shading and can pick detail out of a model easily as well, the only disadvantage is that if inks are not used right they can appear blotchy, gross looking, or generally bad. Look up some ink tutorials to see how to use them correctly.
2. Blending, this is ALOT harder and requires a couple of things, good paints and brushes (fine detail brushes can help but a brush that can cover a good amount of paint should be preferred) general understanding on how light falls on objects and how to translate that to proper blends on a model, and finally steady hands and sharp eyes. When blending keep the base color pretty thick, you dont want to water it down alot and apply enough coats to make sure the base color is consistent and doesnt have any black, or white, or whatever showing through the color. Then apply the first highlight, this should be slightly brighter than the base color, it should be wattered down a little so it doesnt show up drasticlly different. Then apply a slightly lighter color than that ( an alternitive would be to mix white more and more with the base color you used but this should be used only when you dont have avaliable paint) and keep making the paint brighter until each layer is blended with each other, getting lighter and thinner the closer you get to the highlight like this
| [base [highlight-1 [ highlight-2 [ final highlight ] highlight-2] highlight-1] base] |
with enough practice you can get good results but might be too daunting to a beginner.
3. Dry brushing. The easiest technique i know. Do a base color. Take a slightly brighter color. drybrush entire model. then pick details out different color.
hope that helped
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