This is weird; I literally just wrote a (long-ass) email to a blogger friend yesterday when she asked me this same question. Most of my advice was specifically tailored to her, though, so I won’t copy-and-paste!
1. Do your morning pages. They’re explained in detail in The Artist’s Way if you’re interested, but basically they’re just three longhand pages of stream-of-consciousness writing done first thing in the morning when you wake up. (I usually pee and fill up my water bottle before sitting down to do my morning pages, but, y’know, close enough.) They are often really boring and whiny, but the point isn’t for them to be interesting to read; the point is to clear out your brain and jumpstart it and get your writing muscles moving. I know it sounds a bit ridiculous or unlikely but it REALLY does help with productivity and creativity. When I’m doing morning pages every day, I’m a writing MACHINE, brimming with ideas and energy to work.
2. Read a lot. You can’t be a writer if you don’t read, IMO. But don’t marry yourself to one particular writer or genre, or you’ll end up a copycat. Read a wide variety of things, including (but not limited to) the genre(s)/medium(s) you aspire to write in.
3. Work on your spelling and grammar if that’s a problem for you. Spell-check will not always save you; in fact, it will frequently fail you.
4. Keep a notebook, index card, iPhone note, or some other similar thing – anything which you can keep on your person 100% of the time – to jot down ideas when they come to you. Trust me when I say that ideas, even good ideas, can disappear off the face of the earth sometimes if you don’t make a note of them somewhere. It’s so fucking useful to have a list of blog post ideas, pitch ideas, etc. to refer to when you have the time/energy to work – it’s really a hack against writer’s block because you let the ideas in as they come and then use them as you’re able. Inspiration and energy don’t always strike at the same time so develop ways around that fact.
5. I like George Orwell’s writing tip about how you should avoid using any phrases/metaphors/figures of speech that you have ever seen in writing before (“sick as a dog,” “manicured lawns,” “crazy in love,” etc). I don’t believe you should avoid these sorts of phrases ALL the time, since they can be used to great effect on occasion – but it is usually more interesting to come up with your own way of phrasing whatever you’re trying to express. Writing feels punchier and more memorable when you use metaphors and phrases and figures of speech that the reader has never heard before, and has to really think about and process instead of just glossing over.
6. Edit. Proofread. Read your shit out loud. Read it to someone else. Look for holes in logic, missing words, unclear ideas, unexplained assumptions. Make sure everything makes sense and would still make sense if you were a reader who had never heard of whatever you’re writing about.
7. Figure out what sorts of environmental triggers help or hinder your productiveness, and set up your workspace(s) accordingly. I like soft instrumental music, a comfortable temperature, clothes I can move in, a big cup of tea or coffee and lots of water, good light (preferably natural), and minimal technological distractions. That’s the ideal; I’m not always able to achieve that, but those are the conditions under which I write best. Figure out yours and make ‘em happen. If that means you have to buy some stuff to upgrade your space (oscillating fan, looseleaf tea, new lamp, better speakers, whatevs), do it if you’re able.
8. Make your first sentence and first paragraph interesting. If they’re boring, the whole piece will fail.
9. Look carefully at your verbs and adjectives – all of them, if you have that kind of editing time – and replace the more boring/mundane/ordinary ones with snappier, punchier, more unique and interesting ones. You can convey a more specific message with more specific words. Sounds obvious but it’s true and worth considering. (It’s like that scene in Dead Poets Society… “A man is not ‘very tired,’ he is exhausted… He’s not ‘very sad,’ he’s morose.”)
10. Heed that now-somewhat-famous Ira Glass quote about how beginners in creative fields often have tastes that far exceed their talents. Your talent will catch up to your tastes. There will be a time when you like what you write, if you keep at it, even if you think you’re no good now. Get your 10,000 hours in (that’s a Malcolm Gladwellism if you feel like researching it).