How do you stitch quarter and three quarter cross stitches?

These kinds of stitches are simply portions of a cross stitch.

A quarter cross-stitch is one of the extensions from the center of a cross-stitch. These stitches can be worked from any corner in toward the center as shown in examples 1 - 5. A three quarter cross-stitch is a combination of a quarter stitch and half cross-stitch.