I rarely wash fabric
I don't press anything til the block is finished
I don't iron wrinkled fabric before cutting it, a plastic see-through template does it well enough
I don't change a blade til it hurts my wrist to press so hard
All colours go together
Sometimes use 1/4" of selvage for seam allowance
Use fabric scissor to cut paper if paper scissors aren't within reach
Fudge on seam allowance if I need to
Can't think of any others, but I probably break them too ... am a Taurus - stubborn, bull in china shop