Editing, editing, editing. If you don't do it, you've been the victim of it. As a professional grows in their career, the chances of having to do it increase, since you'll often be looking over your employees' work. As an editor, I'm constantly looking over others' work, and the last thing I want to do is discourage them
One of the biggest misconceptions about editing is that it's all about typos and punctuation. It isn't. A good editor will make your writing not just more correct, but also clearer, easier to read, and easier to understand.
When possible, I try to let the writer have at it in between each read, although sometimes the process does get squished together (then reads one and two usually blend together). My editing process usually goes something like this.
Don't pick up the pen just yet (I have to remind myself of this every time).