START A NEW PIECE OF YARN
In order to ensure your finished piece isn't spoiled by loose threads and lumpy knots, it's important to start each piece of yarn correctly.
To begin tie a knot in the end of your yarn and go down into the canvas about 1 inch away from where you want to stitch. Try to remain within the same coloured area to avoid colour contamination if you can. Your knot will be on TOP of the canvas.
Next, come up in the area you want to work and stitch towards the knot. The yarn will be secured underneath as you stitch over it. Once you approach the knot you can snip it off by pulling it upwards and cutting the yarn as close to the canvas as you are able to.