Best Writing Advice?

I’m feeling a little lonely here lately, so I thought I’d post something you all might want to comment on.  I’m interested in hearing what is the best writing advice you ever received?  It could be from a book, from the web, from critique, or from a teacher.  What advice have you been given in regards to writing that has most impacted your work?

Mine would have to be, “If you want to write, just write.”  We hear that a lot, but it really does relate to me.  My best writing comes when I turn off my inner critic, turn off my doubts of planning or whatever and just write.  It may be crap at first, but it is progress.  There is no such thing as someone who wants to write.  You either write or you don’t.

Please post your advice in the comments of this message.