Arabesque is a very common position in classical ballet and can look very impressive from the view of an audience member. However, its important that a dancer not cheat an arabesque line by trying to open it to the side in an effort to get their leg higher. Stay classical and clean by remembering to keep your arabesque leg behind you.
If your leg goes down a couple inches, don’t worry, simply try getting it back to the same height but correctly. Like other steps in classical ballet, the height of an arabesque doesn’t mean much unless its done correctly. A high arabesque really isn’t an arabesque if your leg isn’t directly behind you and instead pointing off to the side. From the front, while it may look like your foot and leg is higher, you’ve actually shortened your line by a couple inches.
Also, this cheat of opening your arabesque has absolutely no benefit to partnering and makes it very difficult for the male to understand your position. Lastly, by having an open arabesque, you’ve made it more difficult to do more advanced steps that require a solid arabesque, for instance, saute or cabrioles in arabesque or a coupé jete among many others.