As you become more proficient, you start picking up little tricks to improve projects
One of my favorite things to do is add a selvedge edge to a scarf. I like a slipped-stitch edging, which gives any scarf pattern a nice, finished look. Just add 2 stitches to the stitch count. Slip the first stitch of every row purlwise with yarn in front (WYIF) and knit the last stitch of every row. Presto: a lovely detail that is simple to add.
In the case of the fingerless mitts, I bound off using Jeny's Surprisingly Stretchy Bind Off. This bind off method is - as advertised - surprisingly stretchy. It works best for edges where you are pretty sure the edge will lay taut when the item is worn, like the top of a sock cuff, or the bottom edge of a hat. If the edge is worn slightly loose, it will tend to look a bit ruffly.
The best way to learn this bind off is to watch Cat Bordhi's tutorial here on YouTube.
Another thing I have started doing is using a tubular cast on for everything. There are a lot of ways to do a tubular cast on. I tend to favor the one I learned from the Grace Lace Beret pattern. It accomplishes the whole thing in three rows of double knitting.
You cast on half the number of stitches you need with a provisional cast on, increase in the first row, then work two rows of double knitting. On the first round you knit and slip alternate stitches. On the second round you slip and purl alternate stitches. This creates a tube with the magic of double knitting - thereby putting the "tubular" in "tubular cast on." Then just unzip that provisional cast on, and knit away!
This cast on looks nice and tidy, leads well into 1x1 ribbing, and is also very flexible and stretchy. I wasn't thinking when I cast on for these mitts - I just used a long tail cast on, which feels a bit tight. If I could go back and do it again, I'd do it tubular, for sure!