Cut tubing squarely and fully engage onto barb.
Double wrap without crossing wire on backside.
Cross tails, take up slack & ensure wire is not too close to tube end prior to twisting. A needle nose pliers works well here. Twist wire about 1/4" Do not be too concerned if a small gap under twist is present as the second wrap provides tension.
A slight dent in the tubing is all that required for positive retention. Too much and you can cut through the tubing. Trim wire end and fold down. A peice of shrink tubing can even be used to cover sharp wire ends, just not inside fuel tanks.
Backside detail showing no crossed wires.
Smoke systems are accessory items and may void your engine warranty. Consult your engine manufacturer for specifics. BDS assumes no responsibilities for damages incurred due to improper installation or setup.