Well, it's not really 'my' technique, so much as the technique and learned and now use to create my digital paintings. It is involves five main steps: 1)block in 2)highlight and shadow addition 3)gradient blend 4)detail 5)contrast. This will create a black and white image; I'll show you how I colourize paintings another time.

First thing you need (as always) is reference. I have said this before, never paint anything without reference. Even if you are doing a stylized painting (such as a cartoon), use real reference. The best artists of all time used references, you should do no different. You will be a better artist when you use reference and frankly, it's pretty arrogant if you think you don't need it.

Here is the reference I am using today.
Yes, this photo is too small and pixelated. But that is ok. We can clearly see the contours of the hand, the highlights the shadows and quite a few details. Also, I am considering how small the hand will be in my completed painting. I don't plan on giving this hand lots of finite details because of this and also because it is not the focus of this painting. In this tutorial, I will show you how to paint a hand with a reasonable level of detail.

The first step is blocking in the hand. Make a new layer and set your paint brush to %100 and make the hardness quite high. Block in the basic forms. Use 2-5 tones but no more than that. Here is my block in:

Next, add the basic highlights and shadows. Make a new layer and set your brush to %70. Paint on the highlights and shadows from the reference.

Merge the block in layer and the highlight/shadow layer. The next step is gradient blending. Right now, the painting is very blocky and sharp. We want all of the tones to be more blended, similar to a gradient. The way I do this is to set my brush to %30. Pick and area you want to blend and sample the colour. Paint over the 'seam' of the two colours. Sample the new colour you just painted on and paint over the 'seam' again. Continue this method intil the two colours gradually blend together. I have used this technique here in the web between the thumb and pointer finger.Continue to use gradient blending to smooth out the colours. Keep checking against your reference; it's very easy to become focused on gradient blending causing you to eliminate the key details you have already blocked in. Keep making your brush smaller and smaller to create and maintain details. Change your brush opacity and hardness as appropriate. You can also use the smudge tool to blend tones.This is looking pretty good, but I think that I have lost some of the contrast I had before. A good way to increase the shadows and highlights is to use the dodge and burn tools. To increase the highlights set the dodge tool to 'highlight' and the exposure to %15-%30. Brush over the highlights with the dodge tool. Do the same thing with the burn tool, but set it's exposure to shadows. Match your reference!This is as far as I am going to take the hand detail-wise. When you see my completed piece (it will be completed in a few days), you will see this is the appropraite level of detail. You need more detail? Then you will need better reference. Use the same techniques described above. Start with big blocky strokes and work your way down to the small details. Make sure you are constantly checking your reference and you just can't fail!

I hope you found this tutorial helpful, thanks for reading!