For instance, you might be walking along, not thinking of anything. You turn into a side street and there, at the end, is a rubbish dump leading on to a railway yard.
You stop, surprised. It looks wonderful. All those shapes and textures and the pattern of the railway lines and the wires in the sky. The light striking across the grass. How marvellous to draw, you think. It has everything an artist could want.
Then you pause. Your mind steps in. Now, now, it says, you can't paint that. It's ugly. It's horrible. What will the neighbors think? In short, it's a disgusting subject to choose. Who would want to look at that? and so on and so on.
Nuts! Who cares what the neighbors think? It's none of their business anyway. Who cares if it is considered a disgusting subject? It isn't a disgusting subject at all. The disgust comes from the prejudiced mind. The subject, in fact, is a good one for working out colors and shapes and tones and patterns and the like. Now what could be better than that?
It is the associations that make a subject seem unpleasant and associations don't make good pictures. You have to shed those associations slowly if you want to enjoy working outdoors, otherwise you may have to walk for miles and never get anything done. If you can gently persuade your mind to accept the idea that it is not the niceness of the subject that matters but the inherent qualities in the objects, their shapes and colors and so on (because these are the qualities you will be dealing with) you will have no difficulty at all in choosing subjects.
All subjects, then, will be grist to your mill. Canals, stations, streets, scrap-heaps, junk-yards, landscapes, rivers, docks, backyards, alleyways, car parks, roadside cafes, ruins, derelicts, new buildings, old buildings, small parks, large parks, looking up a hill, looking down a hill, rain, sunshine, autumn and winter, all the things around you that make up our daily life. All this will supply you with the stuff of painting and sketching. How you treat it and in what form is entirely up to you.
The acceptance of shape and color, tone, and so on, over preconceived notions of beauty and ugliness will also help you to understand a great deal of what has gone on in art in our time. Gone are the notions that it is the subject which is chosen which ultimately grades the picture into good or bad art.