Hi Steve, there are a number of techniques used in each image, usually takes me an hour or more to complete one. To long to explain in a forum post. Its whats known as ‘the painterly effect’ there are different ways to achieve the effect.
Without sounding rude, there are lots of YouTube videos on this effect, I just follow one I like the look of, then apply my twist to it, everybody has a different style to what looks good to them. I also use bog standard Photoshop, no plugins and maybe install a few brushes to add back some details that get lost in the process. I also have a graphics tablet which helps a lot, but can be achieved with a mouse, if you have a steady hand
Hope this helps and thanks for your interest