We all have them--those go-to words that litter our first drafts but also happen to be invisible to the writer's eye. It isn't until someone points them out that we go, "Holy crap! How did I not see this before? I've read this draft a hundred times!"
This is where a great beta reader comes in handy. If you don't have a beta reader or two, then get one. I can't express enough how much EVERYONE needs a trusty beta reader. In fact, one of my beta readers has actually been promoted to ALPHA reader because she's that darn awesome. I couldn't imagine writing a book, any book, without her reading it first. She's constantly catching things I miss and causing me to feel foolish. I love her so much.
For me, a few repeater words I find myself using over and over are JUST, BUT, and SO. Now, don't get me wrong. There are cases in which these words are needed, so don't go deleting every single one of them from your story. What I'm talking about is EXCESS and UNNECESSARY uses of the words to such a point that they become the only thing the reader sees. That's not good.
I think the best way to find those pesky repeater words is to use a beta reader. That's my preference. Not only will they point them out for you, but they will find other errors and plot holes for you as well. Having a second set of eyes can do amazing things for your manuscript.
But I understand the hesitancy to hand out manuscripts, especially rough drafts, to just anyone. I get that. I do. If a beta reader isn't an option (you really should make it one) then there are other ways to search for those repeater words.
Try ProWritingAid. It's free, though it does require registration. You simply paste in your text and any duplicate words will be highlighted.
Another option is to use the find and replace tool. If you're worried about using a certain word too much, type it in the find tool and go hunting for it.
However you decide to look for the repeaters and go-to words, you just need to make sure that you do. In most instances, you will find the overused word simply needs to be deleted. It does nothing to add to the sentence. Again, don't delete them all. Some paragraphs and sentences will sound better with a JUST or a SO slapped in there, especially in dialogue, but do look for ways to mix it up and remove them where possible. (Just and So are my repeater words. Yours, most likely, will be different).
The first step to repeater words is being aware that you have them. I promise that you do. Embrace the knowledge and then go do something about it.
Now, I'm off to delete those nasty buggers from my own work.