I have to make a bust of Alexander the Great for my history class. My teacher said that since most of us probably aren't very artistic, that you should try to focus on certain aspects.
Was he known for having a small nose or large ears or something along those lines? Something that made him stand out or distinguish him from others around him?
His most prominent features were most likely his eyes -- according to Arrian, Alexander had heterochromia, which is when one eye is a dark color and the other is light. He also had a slightly twisted neck. Plutarch describes it as being slightly bent to the left, and most busts of Alexander reflect this feature as well (ex. two busts by Lysippos, who Alexander supposedly felt captured his likeness most effectively).
As /u/Juvenalis says, Alexander's youthful curls are rather distinct, though it's important to remember that coins and busts often served propaganda purposes as well. The curls emphasized his youthfulness and also evoked the perfection of the gods. You often see later classical figures attempting to mimic Alexander's look -- Pompey Magnus, for example, deliberately wore his hair in the same curly style.
His hair was probably his most recognisable feature.It's one of the main means of distinguishing his head on the coins struck by his 'successors' ( see e.g. http://www.britishmuseum.org/explore/highlights/highlight_objects/cm/s/coin_with_head_of_alexander.aspx ). Other coins used 'elephant hats' to remind us of the 'conquest of India ( https://upload.wikimedia.org/wikipedia/commons/7/77/PtolemyCoinWithAlexanderWearingElephantScalp.jpg ).
Later depictions of Alexander seem to pick up on this feature; see e.g. this C1-2 CE bust ( http://www.britishmuseum.org/explore/highlights/highlight_objects/gr/m/portrait_alexander_the_great.aspx ).
