If you were to ask me for writing advice, I'd have to say first and foremost that you should...write.
The next piece of advice I would give is...
read writers/authors who write better than you do.
Why? Because you are what you read. If you want to improve as a writer, spend the bulk of your time reading stellar writing. In any given genre, there are those authors that stand out. Sometimes bestseller lists are a key but don't be fooled.
The unique thing about reading writers who write better than you is that the books that impact you will often be different than the ones that impact me. Don't confine yourself to the CBA. There are many incredible books outside the CBA that are clean and amazingly well done.
The danger in reading higher level writing is that after awhile you'll not be content with anything less. Your reading basket will be thinned - your TBR pile will not topple. You'll begin many a book only to set it aside.
I truly believe that you are what you read. A friend in Canadian publishing and I were recently discussing this. She'd written her honors thesis on how the fiction read by L.M. Montgomery (Ann of Green Gables, The Blue Castle, etc.) in her formative years influenced her own fiction so profoundly later on.
Now that I have the gift of hindsight (a nice way of saying I'm getting older:), I have a few years of reading to look back on and can name the books that have most influenced me. Here's just a sampling...
~Christy by Catherine Marshall
~Redeeming Love and Mark of the Lion Series by Francine Rivers
~The Blue Castle by L.M. Montgomery
~Follow the River, Long Knife, From Sea to Shining Sea by James Alexander Thom
~Song of Years by Bess Streeter Aldrich
~Jane Eyre by Charlotte Bronte
~every book by Victoria Holt aka Philippa Carr and Jean Plaidy
~every historical epic by Allan Eckert
If you're a younger writer, you're forming your list this very minute:) If you've logged a few miles like me, you'll have a shelf of best loved books on hand that stand head and shoulders above all the rest.
What's the best piece of writing advice you've ever received?