My Specialty is to Maximize Frequent Flyer benefits; but for "cool Cities" I suggest the following:
MIA-SFO

, SFO-DFW-BOS

ish, BOS-LON-AMS (don't park in UK, ever: tax is shocking), Recover from AMS then, AMS-LON-DXB, DBX-LON-HKG, HKG-NRT

(look closely, Narita is fine), NRT-HKG

, HKG-SYD, SYD-PER-CBR then hitchhike back to SYD

.