Question for the group: how do you deal when you write a bunch only to feel that they're not very good words? Do you just keep throwing words at the page and resolve to edit later? I feel that my slower, more careful approach might not work during NaNoWriMo where the focus is on writing lots.
It depends on what words they are.
First off, sometimes you will just have a bad word day. Not a day where you cannot write, a day where the stuff you write is stuff you immediately dislike. Keep it, try and work on other stuff, and come back later when you've had more time to think to look at it again.
It is possible that working from there will lead to stuff that makes it look better, or that you just weren't in the mindset to realize it was alright. It could also be the case that it is still trash later, but you have a better idea where you are going to rework it better. It could also be just meh, and you can either leave it, change it, or remove it when you get back to it depending on how bad "meh" looks in that spot.
If you have written those words and are struggling going forward from them, then it might be a case where you need to set them aside (I put them elsewhere in the document with a scrap label) start that part over, and see where it could have gone another way, maybe take a break if you don't have another idea yet. I recommend keeping them because sometimes there is something in there that will work elsewhere later, or a break might make you change your mind about them.
Generally I've personally found that when words aren't coming it isn't worth it to force more. Trying to make notes about where to go, or plotting out future stuff is a good backup, and is progress even if it isn't directly creating more wordcount.