Knitting stockinette stitch + edge stitches

Dear users, dear authors,
Do you have any tips on knitting stockinette stitch and also on knitted edge stitches?

I slip the edge stitches without knitting them at the beginning of the row—except for the first row—and knit the last stitch.
 

When knitting stockinette stitch in rows, you have knit stitches on the right side rows and purl stitches on the wrong side rows. As a beginner, you often knit the knit stitches more loosely than the purl stitches because they come more easily. So you should make a conscious effort to knit them a little tighter to achieve an even stitch pattern.
As for edge stitches, everyone probably has their own preference. I haven’t found a favorite method for myself yet and tend to switch it up from time to time (though not within the same project, of course).

No matter what pattern I’m knitting, I always knit the last stitch of the row, and I always slip the first stitch knitwise—that’s when the edge turns out the smoothest and prettiest, in my opinion.

For me, it’s exactly the opposite: I knit the knit stitches very tightly, but the purl stitches always turn out a bit loose, and I have no idea how to fix this—it can be really annoying when I’m knitting socks. But no matter what I try, the purl stitches end up loose again.

I’m in the same boat as Veronika-115. That’s why I use a needle half a size smaller for the row with the purl stitches. That evens things out pretty well.
I also knit the edge stitches at the end and slip them at the beginning.
I once saw a tip somewhere on how to get a particularly nice edge stitch (if you don’t have to or don’t want to sew the pieces together or knit a cuff). It worked by making a yarn over before the edge stitch, which is then knitted together with the edge stitch in the next row. It makes the stitch a tiny bit thicker but also tighter and creates a nice finish. I tried it once and thought the result was great. Unfortunately, it’s been a while, and I didn’t write down the exact details, so now I’ve forgotten exactly how it works.
But I’m sure there are experienced knitters here who are familiar with this and know how to do it.

Since I don’t really like sewing pieces together, I often knit in the round. The problem is that my knit stitches are very even when knitted in the round. But as soon as I switch to knitting in rows, my stitches don’t look as nice anymore. 

I feel the same way, Petra.

That tip about using a thinner needle for the wrong-side rows is great—I’ll definitely give that a try.