Back stitch

Back stitch is the strongest of all stitches. They form lines and are most often used to outline shapes or to add detail to an embroidered picture. 

How to do back stitch:

1. Thread needle and bring up through fabric. Then bring needle down through fabric. Repeat sequence 2 times, going over the previous stitch. This will be more secure than tying a knot.
2. Bring needle up a stitch length away.
3. Bring needle back down to where you started.
4. Bring needle up at stitch length away from step 2. 
5. Repeat sequence.

As you will see, your stitches are going forward, then backwards.

The yellow stitch above is the back stitch. The green stitch below is the stem stitch. 

Always try to have straight stitches.