This crochet stitch tutorial shows how to make the V stitch (v-st). Is is quite simple and consists of two double crochets (dc) worked in the same stitch with one chain (ch) in between. The V stitch works great with multiple colors.
This crochet stitch tutorial shows how to make a cross stitch double crochet (cross-st-dc) or a double crochet cross stitch.
This crochet tutorial is for making an increase (inc). If you want to make an increase, just make two (or more, depending on your pattern) stitches in one stitch of the previous row.
This crochet tutorial shows how to make a half double crochet slip stitch back loop only (hdc-slst-blo).
This crochet stitch tutorial shows how to make a half double crochet slip stitch (hdc-slst).
This tutorial shows how to work in the third loop only in the front. To make this stitch you need to have a previous row of half double crochets. Here it is shown how to make single crochet third only in the front.
This tutorial shows how to work in the third loop only in the back. Similarly like working in the back loop only, working in the third loop only is done in the same way for all stitches.