Since nobody but nobody ever remembers who has the legal right of way at intersections, I'm overly deferential when it comes to these situations-- I prefer the other guy make their move, then I will go when it's safe.
That said, often enough it gets into one of those "You go, no YOU go" standoffs that benefits no one.
So, here's a helpful intersection tip I discovered MANY years ago: if you come to a stopping standoff at an intersection and you want the other driver/rider to turn before you, do the quick wave, but THEN turn your head away to not look at them.
You could spend five minutes waving somebody on and they won't bother turning, but the moment you look away from them (bonus if you fiddle with your gloves/tank bag/etc.), they'll take the initiative and turn. Works 90% of the time IME.
Basic driving psychology: just as we riders should never assume that a driver looking left won't turn right, drivers all the time assume that if you're not looking at them, they're free to turn.
Another bonus: works great if you're a pedestrian, too. At a crosswalk if you want a car to turn before you walk, just give one wave, THEN turn to face the other direction.