Just started a new self portrait, using a canvas that I recently made with Natural Pigments lead oil ground. The beginning is always rough and I'm not going for any detail at this stage. I think of the beginning like the understructure of the painting. Portraits have a lot going on, but they need to progress gradually. It's good to keep the beginning malleable instead of committing to some exact detail such as a highlight. The painting gets more delicate as more modeling is added so it's not good to jump to details right away. The beginning has some slight indications of general details, but nothing concrete in case I have to adjust some proportions.
As I said, I'm using a lead oil ground; lead oil grounds are very different from titanium oil grounds. Lead has a really nice level of absorption that also repels a good amount of the paint laid on top. I've noticed that titanium white grounds absorb a lot of the paint and it feels like you have to pile on the paint just to get any level of impasto. If you're a painter that likes thick paint applications then I encourage you to use a lead oil ground.
I'm going slower with this painting and with more of my old intuitive approach. I still like alla prima painting, but I can't get the level of detail and modulation of tone with pure alla prima. I already paint fast and I feel the need to slow myself down and let it dry when necessary in order to build up the detail. I'm excited to work on this more and will post more as it progresses.