The main trick to speedpainting is not overthinking on the details. Instead of going right in and focusing on smaller details like eyes, lips, scenery, etc. focus more on the big picture. Block out shapes with the use of color separation and thick line use. Get the general idea of the painting down, and then work your way into the details bit by bit, while still focusing on the entire drawing.
And of course, don't feel pressured to be super fast right away :> The joy of speedpainting is in just being able to sit down and let your imagination run wild for 10, 20, 30+ uninterrupted minutes. If you end up spending an hour on a painting, don't consider it a failure. The goal isn't to be the fastest painter in the world, the goal is to bring the colors and imagery in your mind to life on the canvas. If you feel pressured to work faster, you'll just end up psyching yourself out and all the enjoyment in it will be lost. If you really want to learn how to do those fast speedpaints, then just practice. Once a day, sit down, do a speedpainting. Your time will get better and better the more you do it.
That's pretty much all there is to it /shrugs At least all I can tell you. Be sure to find some tutorials and watch lots of videos to see what kind of techniques different artists use :3
