The art of choice these days seems to be large canvasses painted in abstract. Not my choice, but obviously loved by many people.
I don't understand why, when people live such busy, noisy and stressful lives, they like to hang a large loud painting of streaks and blobs in their homes. 
After a busy day, I would think that a calming, peaceful painting of a landscape or water or mountains to look at , would be much more pleasant and restful.

A 'country girl', born and bred in a rural area, told me a few years ago that "Trees grow to the shape of their leaves". How had I gone all of my life without knowing this? After I had this knowledge I looked at trees in a different way. It is true, and is particularly noticeable in the Wintertime, when branches, bare of leaves, are silhouetted against a Winter sky. Take a look, a maple leaf has 3 basic points, so do the branches.  An oak leaf has 7 points, and of course, pine/fir trees grow to a triangular shape and so do their leaves. Even during the leaf laden times, an unadulterated tree still holds the same shape as it's leaves.
I have found that to paint a realistic tree, I have to really study them. I watch how the sun hits the branches and leaves, changing the colours. How a tree will have swathes of lighter colours into dark depending on the light, and especially how the colours of the leaves will change with the wind as they flicker and shake with the breezes.
I find it interesting how , when close to a tree trunk, the bark has many colours, from dark brown to pale grey, lots of crevices and nodules, that are not visible from even a few feet away.
All this info helps when painting trees into my artwork, and helps my paintings to look more 'lifelike'.