Anchor bargello with a waste knot

Bargello Love says,

Unlike other needlepoint stitches, the Bargello stitch with its long and somewhat loose effect can cause a problem when anchoring the first stitch of a needlepoint project. The best way to solve the problem is to use a waste knot to secure the beginning strand, which can later be clipped off and removed.

See the tutorial on Bargello Needlepoint.