Debbie Bliss pattern help needed

Making DB ribbed cardigan (free on Ravelry). K3, P3 rib mostly. Increases required (12 on back). Pattern says K3 m1 on increase rows but doesn’t explain whether to knit or purl on following rows. After 3 increases, I have 6 knit stitches at either end of right side. What should I do?

Welcome to KH!
Usually the instructions tell you to incorporate the increases into the pattern, in this case the k3p3 rib when you can. I usually increase as knit sts and on the next row, work that increase into the pattern ether as a knit or a purl.
This most often happens on sleeves but can certainly be part of shaping the body of a sweater.
There are a couple of DB ribbed cardis on Ravelry but maybe this one?

Thanks for that. It just looks pretty untidy whichever way I do it. I’m either adding knit stitches or purl ones each time. Never had this query before, and I have been a relatively proficient knitter for many years! It’s usually easy to fit increases into the pattern!!!

And yes, that looks the same although the photo is different.

The other thing to consider is that the increases will probably fall into the seam, especially if you make them on the edge sts instead of a stitch or two in from the edge. Even one stitch in from the edges still puts them at the seam and barely noticeable.