PROBLEM: Your handlebar tape loosens and shows gaps, especially on the top curves just behind the brake levers.
SOLUTION: Re-wrap the tape starting at the bar end and finishing near the stem.
When tape is wrapped the other way, from the center to the end, your hands push against the overlap along the top curves. This rolls the tape's edges and eventually opens gaps.
Buy new tape or reuse what you have if it unwraps without tearing. Start at the very end of the bar. Pull firmly and overlap uniformly about one-third of the tape's width. Beware of gaps on the front side as you wrap around the big bend.
Roll back the rubber hood and do a figure 8 around the brake lever. For a pro job, first put a piece of the bar tape around the lever's metal band. Then no gap will show when the hood is put back.
Continue wrapping snugly to about one inch from the stem (or to the edge of the bar's raised center section, if it has one). Cut the end and secure it with a piece of electrical tape. You get bonus points for using a color that coordinates with your bike.
Voila! Another nuisance quickly negated. The tape should stay perfectly in place. Your hands can't push it apart.
Tip: Always use bar plugs. Those little things are actually a safety item. An unplugged handlebar could take a core sample from your leg if it were to hit you in a crash.