Possibly one of the worst pieces of advice I see writers telling beginners is to "feel free to write crap."
This is intended to encourage beginners to turn off their internal editors and internal censors, freeing them to put something--anything!--on the page. The belief is that something on the page can be edited later; a blank page can't be fixed.
This leads to sloppy writing and far too much time spent at the back end of the creative process, trying to turn all that crap into usable compost and then to grow something worthwhile in the compost.
In no other profession is it advisable to do bad work on purpose. Imagine if my cardiac surgeon had approached my bypass surgery with this attitude: "I'll make a couple of cuts and toss in a few stitches. It's only a first draft. I can go back later and clean it up."
I believe writers should always strive to write the best they can when they put pen to paper or fingers to keyboard. Always striving to produce the best writing means more time spent creating and less time wasted polishing turds.
Do I sometimes write crap? Absolutely, but never on purpose.
When I sit down to write I produce the best work I can at that time on that day. If it turns out to be crap, I deal with it.
But I never "feel free" to write crap.