Yeah it's not easy this stuff and I've probably in some ways chosen a very difficult subject to paint in that primarily it appears to be white, whereas it's hues of whites containing a whole bunch of colours and getting the depth of the hue correct is proving to be quite a challenge. The other aspect is knowing when to stop. Years ago I wouldn't have been happy unless the painting looked like a photograph, but I'm a lot more laid back about the work and I'm hoping that the painting will look like a painting rather than a photo in this instance, but the old style painter still lurks beneath the surface wanting the detail to be there so that it feels complete. Painting a white jumper with texture in using acrylics does seem a bit of a mammoth task and at the moment I am struggling with the question of how much detail do I need to include. Another worry is whether at the expense of going for a more painted approach, the image might look carton like and I also want to avoid that as well.
Another issue is the artist that I'm being influenced by has an unusual style that includes hideous mistakes and his work retaining various levels of detail differing from one to the other. While I'm not copying what he does, I'm using his approach and parts of his technique/style to inform my own work and develop my own style when painting with acrylics.