A trick I've seen Khal do many time to check the entire chain of Handles, Lines and Kite is to put the kite in launch position, Place the handles together exactly side by side and launch, If the kite rises vertically, you are good to go.. If it drifts or turns then adjust, lines, knots or bridles accordingly..
Everything might be perfect line wise and you might find the smallest kink in the bridle or the knot is twisted or some other thing you wouldn't notice otherwise....
New lines especially might need to be equalized a few times before they are "locked in" pretty well..