Oh, serious, deadly serious?

Avoid a style like the plague. If you become stylized, so you can only draw an eye like this, a hand like this, a face like this, it is really fucking hard to get out of that style and all your art will end up looking the same.

Use different techniques by all means, and draw what you like, but if you ever find yourself saying "This is what an eye looks like" or "This is what a nose looks like, know you need to reassess.

In my view, you should actually avoid artists while just learning the craft of drawing. Have a look at the philosophy of art, find out why people do things as they do, but make sure you are not just growing into a copy of an artist you like. However good Michelangelo is, we don't need two of him.

Other than that, find the tools you like. If you like hard pencils, use them! Don't let any guide (or art teacher) tell you that 2B is the 'sketchers' pencil, or tell you that you can't draw with pens on first draft. I have happily drawn with metal points to good effect. Use the tools that suit you. A good artist can draw a masterpiece with a chunk of chocolate.