The average writer whose books have made his name famous, had to write much by way of practice, before any of it found a paying market. And we humbler folk must not be above doing likewise.
Begin to train yourself in writing by making studies, in words, just as the art student makes them in line or wash. Make studies of character, of scenery, of temperament, of dialogue—of anything that comes to your notice and interests you.
To make a character study of someone you know intimately, or with whom you are in daily contact, is a useful exercise—but I don't advise you to read it to them afterwards, that is if you feel you have been quite frank in your writing, and you value their friendship!
Aim to make each study a little word-picture, embodying some idea, or reproducing some trait, or conversation, or incident. But do not be in too great a hurry to embark on a lengthy or involved piece of work.
The Style of Writing should Vary According to the Subject-Matter
Practise various styles of writing—serious, conversational, gay, didactic, colloquial, etc.; and see that the style corresponds with your subject-matter.
Watch good authors with this latter point in view. For example, the style of writing in Kipling's "Barrack Room Ballads" is not the style he used when writing "The Recessional."
Often several styles of writing are necessary in one story, if we are introducing contrasts in characters or in scenes. And though we may think that one style is peculiarly our own, it is most desirable that we should write just as readily in any style. This gives variety and colour to our work; also it reduces the risk of our acquiring mannerisms, which are generally tiresome to other people, though we are blandly unconscious of them ourselves.
But be sure that you do not appear to force an effect; do not make an effort to be light-hearted, for instance, or overdo the sombre tone one would use at a funeral. Sincerity should underlie all your writings; they should carry the conviction with them that what you say happened, actually did happen, and was not invented by you merely to heighten the gaiety or deepen the gloom, as the case may be.
In order to make your style sincere and convincing, you must study life itself, not take your models from other people's books. If you are to write in a joyous style that will infect others with your cheeriness, you must enjoy much of life (if not all of it) yourself, and be able to enter into other people's enjoyment. If you are to make your readers feel the grief that surrounded the funeral of which you write in your story, you must have shared in sorrow and sympathised with others in theirs.