1. Don't eat the crayons, even if "purple tastes gooooood". No, really. Put that down; it's not meant for that.*
2. Young talent must be nurtured. A child who has a certain knack for, say, writing stories in English class needs to be taken aside and told it in order to make them realise that they're special, to encourage them and (more importantly) alienate them from the dickwad jocks around, breeding a seething resentment of their low status in the high school pecking order. Compensatory arrogance and narcissistic rage are the powerhouse of the creative impetus.
3. Writing is 100% inspiration and 100% perspiration. It's what you breathe and what you sweat, all of it, equally. It often stinks for that reason, but not devouring shit will usually improve this state of affairs.
4. Flattery is for fuckwits; ruthless critique is the only critique of any value. Workshops can be valuable then, but if a workshop session doesn't make you want to kill someone** it's not worth shit. Even if it does you probably won't listen to the content and rewrite your crappy mood-piece / novel fragment / background summary so it's an actual fucking story. You will however want to a) get your own back on the bastards b) show these fuckers that you really are a genius, so there. In attempting to achieve the first you will hone your critical skills. In attempting to achieve the latter you will apply those skills to your own writing.
5. Learn to kill your darlings. But torture them first. And after you've killed them, strip the meat from their bones, take them apart and build them into one motherfucking huge serial-killer-style shrine. Alternatively, put them back together and reflesh them with muscle and sinew sliced from your own naked body (or neighbourhood pets) and vat-grown in your underground laboratory; raise them from the dead as a glorious army of skeletal warriors, unquestioning servants in your plan for world domination.
6. Shoeboxes full of adolescent scribblings make pretty fire. Should your army of undead sentences rise up against you, ceasing to obey your every whim and becoming instead an unruly mob seeking equal rights and inclusion in every story or novel you try to write, putting all of them -- every last motherfucking one of them -- to the torch will liberate you to start anew, utilising the skills acquired over five-ten years of twiddling and tweaking. As a wise man once said: exterminate all the brutes.
7. There is really only one way to be a writer: start writing, carry on writing, and keep on writing until it's five in the morning. A mix of uppers (e.g coffee) and downers (e.g. cigarettes) can keep you balanced for an indefinite period on the knife-edge between consciousness and complete collapse. This is known as "the Zone". Remember: sleep-deprivation is the poor man's hallucinogen.
8. Bad writers burrow; good writers steel themselves and face the fucking consequences when the monster they've created gets loose and runs amok inside their heads, raping innocent memories and pillaging knowledge, growing in might and violence until the landscape of the mind is all but consumed in chaos. Fear not. Once you have tamed the monster it will be a loyal friend and ally, demanding only the occassional virgin sacrifice. And that's what virgins are for.
9. "Art" is a poncy term for craft combined with flair. What distinguishes the talented writer from the good writer (c.f. Delany) is having the audacity to take on an insanely difficult project and the panache to fail gloriously, shrug it off and start on another even more insanely difficult project. Pretentious writing is only pretentious because it is not ambitious enough. Your detractors will not make this distinction, but what do they know? Bastards.
10. Fuck that shit.
* 1a. This simple childhood rule applies also in adult life to: playing computer Solitaire; browsing the interweb; checking email; surfing for p0rn. If you are doing any of this you are eating the crayons. Stop it now.
** 4a. If the someone that ruthless critique makes you want to kill is yourself then you are not a writer and never will be. You are a delicate flower... to be snipped off and worn as a buttonhole by men of cruel wit and savage passions.