One of the most common word confusions I see, even in writers who aren't easily confused, is between "effect" and "affect". It's very understandable - both can be a verb, and both can be a noun - and sorting it out is a bite-sized job, so here goes.
It was Julia Cameron who started the idea of the "Artist Date",* in her book The Artist's Way. The idea is that any creative work draws on a well - or a larder is a more useful image, I think - and if you don't want to run out of creative food and therefore fuel, you have to fill the larder and keep refilling it. But how do you fill it?
Another thing I frequently find myself writing on students' work is "Don't pull its teeth!". Here, "it" is a scene, a sentence, a character's thought, or a character's action, which has all the ingredients to be compelling, but somehow falls flat.