Back stitch is usually marked on your pattern as a straight line and is usually worked from the right to the left using one thread unless differently specified in your pattern.

To start, bring your needle up at 1 and back down at 2.

Move left and bring needle up at 3 and back down at 1. Then up at 4 and back down at 3. Go on in this way since your line is complete.

It was easy, uh?

Lets' get into something a little bit more difficult!

FRACTIONAL STITCHES - 1/4 and 3/4 stitches

Half stitch is usually marked in your pattern as an half colored square or as a little symbol in a corner of the square

SIMPLE 3/4 STITCH

You can find this kind of stitch at the end of a stitched area.

That means that if you imagine your square divided in half diagonally, you will have one half with the stitch and one half with just the fabric.

To make an three quarters stitch:
Make a tiny diagonal stitch (1/2 of a normal half stitch) from the corner of the square to the center of the square (step 1-2).

Then make a normal diagonal between the other two corners (step 3-4).

 3/4 STITCH and 1/4 STITCH