1.
Knit through the front of the stitch, just like a regular knit stitch except do not slide the stitch off your left needle.
2.
Bring your right needle tip out to the right side and knit through the back loop of the stitch, sliding the stitch off your left needle as you usually would.
Tip: For a kfbf stitch do the same steps except instead of sliding the stitch off your left needle after knitting through the back loop, knit through the front of the stitch once more.