Hi Dag - I've pm'd you some info
did you want some crit and feedback?
The trees are beautifully simple and understated
The rather surreal one at the top - watch your light source - the shadows are going in different directions, which doesn't read right - I'd look at the work of some of the surrealists if you fancy going that route. It has an other wordly feel.
The bottom one is interesting, looking through the branches with the interesting negative spaces.
What I would suggest is simply playing with watercolours a little before starting another complete painting.
experiment with putting a thin thin glaze of water on the paper (only about 3-4 inches wide/deep as this is playing) and then try putting a smooth wash of colour on - see how the wet paper helps the paint spread.
Now try the same thing but change colours a couple of times as you travel down the wet glaze.
Now do the same thing on dry paper and feel the difference,
With trees and things, have the colours you see in them ready mixed so that you can quickly dab a bit of a different colour and drop it next to the ones you've put down and watch how the edges softly merge.
Try glazing - over previously painted pieces very very gently put a wash of another colour over - no going back and forth with the brush, just one stroke and move on - the underneath colour shines through like stained glass, a very different effect from mixing the colours in your palette.
Use the end of your brush to scratch into wet paint and see what happens - it can create lovely effects.
Don't (obviously) work everything wet in wet or it becomes amorphous and unsatisfying, you do variety.
I hope this is some use to you - painting is a language with a rich vocabulary of marks and the wider your vocabulary, the more interesting your paintings will be.
I'd suggest trying to get a second hand copy (out of print) of a book by Jeanne Dobie 'Making Color Sing' - it's a very very good book for colour mixing/colour theory and does really explain how to make your colours sing.
I'd also Google Kurt Jackson and see if you like his work - I love it and he has the widest vocabulary of mark making and his work is so wonderfully evocative of the places he paints.
Oh and regarding colour mixing - my classes have found it really useful when I gave them exercises on mixing complementaries - see what lovely colours Alizarin crimson and Viridian make - a lovely rich burgundy, through almost black and then into a rich deep conifer green according to the proportions.
Enough lecturing! I just hope some of this is helpful
keep posting
Vivien