Help with Square neck pls

Hello, I am freestyling a sweater and decided to do a square neck. Ideally I’d like to add a 2x2 rib but realised I’m not sure how to “mitre” the corners. Would probably be easier to crochet an edge but would appreciate if anyone had a simple help guide, I searched the internet and very little help. thanks!

I use a centered double decrease for these corners. Some of the videos show garter or stockinette stitch but it’ll also work for 2x2 rib.

Thanks!, so would you pick up stitches all along (adding one in the corner) and then knit but continue doing a double decrease every other row?

That sounds like a good way to try. If the corners don’t lie flat you may have to change but you have to start somewhere. Good luck with-it and please post a photo when you finish.