I've been struggling to do a solid self portrait for a few years now and I figured I'd give it another go today. I did some studies and decided to just do a portrait of my eyes on a long panel that I made. My attempt here is to break down my 2 step process for painting.
The tough part about painting is that it's like building a house. You have to start with a broad plan and base before you can get to the detail. If you're an impatient person, like me, then this can be tough. I want to jump to the details right away but I have to remind myself to keep squinting and slowly build. The same process happens with drawing, except I don't have to wait for paint to dry. ...Not to mention color.
So here's my basic 2 step rundown of how I build a painting or drawing:
Step 1: Focus on shapes and make a solid outline. For painting, I start with a cartoon or draw with vine charcoal on the canvas. Then, I ink the drawing and sometimes put a coat of light varnish overtop. *Make sure if you varnish over your ink drawing to dilute the mixture with OMS, otherwise the paint won't adhere to the canvas. (I found that one out the hard way)
Step 2: Go carefully and gradually build up from broad areas to details. Don't jump to details right away. This step is something that I constantly remind myself of. It's not going to look good right away, use big brushes and KEEP SQUINTING. Think of it like golf, you have to go from a long 300 yard drive, down to smaller strokes.
Of course, there's an endless discussion to be had within this. And I don't want to ever make it seem easy, because it's not easy. But I urge you to keep it simple and never miss an opportunity to learn.