This was a question I have been asked a few times, especially when a learner wants to be able to paint something specific like hair for example. Learners can get very hung up about techniques and how to learn them. Techniques need to be thought of as ways to apply or remove paint to create a visual effect, that is all they really are. Some techniques are extremely simple although at first glance you may not be able to tell how the painter achieved the effect. Some techniques are more complex and require more of a knowledge of materials.
I get asked fairly regularly about certain tools by learners who are confused if they are suitable for art. Often they have been told by previous art teachers that they weren’t tools for artists and in some cases ‘banned’ from the art room. The classic ones that crop up are:
A fine pointed pencil which lengthens when you push down on the top, a bit like a pen, often used for technical art or graphic design.