- When you're working in stocking (stockinette) stitch or reverse stocking stitch (ie knit one row, purl one row) you will slip the first stitch knitwise if you're on a knit row and purlwise (with the yarn in front) if you're on a purl row.
- When you're working in garter stitch (knit every row) you will slip the first stitch purlwise with the yarn in front.
- If you knitted the last stitch then you will need to slip it purlwise with the yarn in front on the next row.
- If you purled the last stitch, then you will need to slip it knitwise on the next row.
Slip the stitch off to the right needle then take the yarn BETWEEN the needles to the back. This is important and where most knitter make mistakes. It's very tempting to take the yarn around the side to the back but if you do that, it'll look like you haven't slipped the stitch at all.
You're know ready to knit the next stitch.
Let's look at how you slip the first stitch if you knit continental. Take the right needle under the working yarn then insert the right needle into the first stitch purlwise.
Slip the stitch off onto the right needle, then take the right needle under the working yarn so that you're ready to knit the next stitch (I struggled to take a photo that showed this clearly but I show how to do it on the Periscope tutorial).