When knitting, you may notice that the first and last stitches on the sides of your piece look uneven and stretched out. There are many ways to handle these stitches so that the edges are more attractive and easier to seam. Some people choose to slip the first stitch purlwise on every row, some choose to knit the first stitch of every row. The most important thing is to be consistent. Some examples are illustrated below in stockinette stitch fabric.
Slip the first stitch of every right side row purlwise with yarn in front and knit the first stitch of every wrong side row. (This neatens both edges.)
Slip the first stitch of every row purlwise with yarn in front. (This neatens the right edge.)
Knit the first stitch of every row. (This neatens the left edge.)