All copywriting, content and editorial teams should have quality assurance processes in place. It's not there to catch out copywriters, but a safety net for writers who are asked to produce engaging copy on subjects they know nothing about at lightning speed.
Or subbing, whatever you want to call it the simplest and most effective way of quality checking your work. There has been a peer-reviewing process everywhere I've worked. And where there wasn't one, I implemented it. It's so important to get a second, fresh pair of eyes on it. And a different brain will help think about it differently or benefit from someone else's experience.
Let it breathe
Even if you have the luxury of putting your work to one side and sleeping on it, do it. It helps to clear the head and forgetting about it sometimes provokes the best ideas.
Sometimes when you've been staring at the same copy doc all day, you just stop seeing it.
In a digital environment, the process of filling an online certificate to make sure all the I's are dotted and the t's are crossed before the page is released into the big, wide world is the last post for checking. Insist that someone from editorial, preferably a senior or above is added to the list of testers.
Read out loud
There are loads of tips on proofreading work, from reading out loud to reading it backwards. However, it sometimes it doesn't matter how much you proofread, if you're too close to it, you'll still read what you intend it to say, not what it actually says. So you'll miss typos or muddle sentences or flow will make perfect sense in your head.
Learn the house style
It helps if you're more than acquainted with your brand's style sheet and tone of voice. Knowing how your company writes dates, times and addresses could save those embarrassing moments with brand.