Jack London offered some great advice back in 1903. They are words to work by for those wanting to get into writing, and direction for most others too.
Don’t dash off a six-thousand-word story before breakfast. Don’t write too much. Concentrate your sweat on one story, rather than dissipate it over a dozen. Don’t loaf and invite inspiration; light out after it with a club, and if you don’t get it you will none the less get something that looks remarkably like it. Set yourself a “stint,” [London wrote 1,000 words nearly every day of his adult life] and see that you do that “stint” each day; you will have more words to your credit at the end of the year.
Study the tricks of the writers who have arrived. They have mastered the tools with which you are cutting your fingers. They are doing things, and their work bears the internal evidence of how it is done. Don’t wait for some good Samaritan to tell you, but dig it out for yourself.
See that your pores are open and your digestion is good. That is, I am confident, the most important rule of all.
Keep a notebook. Travel with it, eat with it, sleep with it. Slap into it every stray thought that flutters up into your brain. Cheap paper is less perishable than gray matter, and lead pencil markings endure longer than memory.
And work. Spell it in capital letters. WORK. WORK all the time. Find out about this earth, this universe; this force and matter, and the spirit that glimmers up through force and matter from the maggot to Godhead. And by all this I mean WORK for a philosophy of life. It does not hurt how wrong your philosophy of life may be, so long as you have one and have it well.
The three great things are: GOOD HEALTH; WORK; and a PHILOSOPHY OF LIFE. I may add, nay, must add, a fourth—SINCERITY. Without this, the other three are without avail; with it you may cleave to greatness and sit among the giants.