There is at least few ways of making one stitch when adding stitches in a knit (like knitting in the stitch below and knitting a stitch from front and back etc.), but my favorites are:
M1R (make one right)
Pick up yarn from behind between sts to left hand needle and K through front loop. This makes a right leaning stitch.
M1L (make one left)
Pick up yarn from front between sts to left hand needle and K through back loop. This makes a left leaning stitch.
I like the look of these techniques; how the stitches smoothly blend to
the knitted surface and how they are easily spotted if you’re in need of
counting the added stitches for example. These leaning stitches also gives you
a chance to play with the structure of the stitches:
In this picture above I’ve worked “K until SM, M1L, sm, K to EOR” and in the picture below I’ve worked “K until SM, sm, M1L and K to EOR”.
My favorite is definitely the latter one. In my eyes it’s a teeny tiny bit of neater outcome.