I find that often the first or last stitch when I turn looks big. I treat the last/first stitch similar to the stitches where I change from knit to purl or purl to knit. I am very careful to pull the tension on the the two stitches before and after the knit/purl change or end of a row a little tighter than normal.
At the end of a row you have much of the weight of the knitting being held by that last stitch. The turning of the piece and the restart of knitting all plays with the tension of the last stitch and first stitch of the new row. It take the friction of two or three stitches to hold your yarn in place.
Knit the last stitch in the row, turn the piece and insert your needle to start the next row. Pull on the yarn and put some extra tension in the last stitch, knit the first stitch of the row and pull the tension a little tighter. Knit the second stitch of the row and again pull the tension a little tighter than normal. The tension of the third stitch depends on the type of yarn, if it is a slippery yarn put extra tension on the third stitch. Normally after two or three stitches with same extra tension I can go back to normal knitting.
I have found that for me the tendency for bigger stitches at the end of a row or ladders between knits and purls is offset by the extra tension on the two or three stitches before and after these stitches.