Learning to really paint.

I haven't blogged for four years, but this summer, 2016,  I've set myself a task, and I think it would be helpful to document my progress.
Over the last couple of years I've thought more about getting out of the studio and working in the open air, making a direct response to the scene in front of me.
Last summer I worked in acrylic in Weymouth and West Bay and in the gardens at Moreton and I've always used watercolour to record directly, but I don't know how to paint, plein air, in oils.
It seems to me to be a completely different and scary  way of working. I use oil paint all the time in the studio, but the painting develops slowly, layers are left to dry and new modifying layers worked over the top. It takes weeks to produce a piece I'm pleased with. How can it be possible to apply the paint in such a way that it's all wet at once and doesn't get mixed up?
My first attempt, a tree on Exmoor isn't too bad, it's a bit boring, there are no real dark places, the composition is poor, but I have got separate areas of paint, there are mid tones and light areas.
My second attempt in Weymouth is so appalling I wipe it off the board before I have a chance to photograph it. The colours are muddy, no definition. What to do?
I study a couple of "how to" books. The one thing all the examples have in common is that the composition is drawn in with pencil before starting. This is totally alien, I never draw for acrylic or watercolour work, just modify as I go along but, of course, that's wet paint over dry. This can't be done that way. But I also don't like the work, it's too close to reality.
So I go online and look for plein air painters who are producing work that I like. I find Robin Leonard, painting in Cornwall, a wonderfully loose style, I think a palette knife is involved in a lot of them, really economical with detail. This is just what I want to do.  And then, of course, there's Tom Thomson painting in Canada just after the turn of the last century. I saw a beautiful exhibition in Dulwich Picture Gallery a couple of years ago which featured his wonderful, crisp, strongly coloured little paintings of the Canadian Wilderness. This is what I want to do too. Looking carefully at Tom
Thomson's paintings, I can see he uses various coloured grounds and sketches the composition with a fine brush and dark colour before applying areas of premixed paint. Each part appears to be only painted once, so all the tonal and colour decisions are taken before putting the paint on the board. Very little subsequent modification is possible.
I think it will help to have a small sketchbook and work out the composition and tonal structure before getting going with colour, a hard set of new rules to learn.
I will post my progress.
Exmoor Beech, Oil on board, 30 x 30 cm