ceigered:
US English pronounces short "o" and "aw" sounds uniquely

I'm not sure what you mean by "uniquely." Do you mean "the same"? It's true that the Californians and many other Western Americans you hear in the movies and on television pronounce them the same, but Midwesterners and just about everyone (except people from Massachusetts and nearby regions) east of the Mississippi distinguish those sounds, pronouncing, for example, "cot" as /kɑt/ and "caught" as /kɔt/.

Ah, that's rather interesting! I had a feeling such distribution existed in the US, but was not sure. By "uniquely" I meant it as a euphamism for "the US "o" and "aw" sound different to how it's said where I live"

In any event, since this joint shows that the "aw" sound in almost every English dialect is either o:, ɔ, ɔ: or ɒː with Canadian English being an exception by the looks of things, the "aw"/"augh" sound is probably the best sound to use as an example to English speakers for an international sounding "o".

witeowl:Here's my pronunciation key, as told to myself:

Pronounce the vowels like you did when learning German and Spanish. Oh, and stop dipthongizing them, you blasted American!

Done.

Hahahaha! Exactly!

I find I actually speak Esperanto with a bit of a Spanish/Rio accent, which is weird, because I've studied neither Spanish nor Portuguese.

My mother grew up in Brazil, so when I hear her speaking Portuguese with our house cleaners, she makes the "O" at the ends of words sound like "oo". So now I do the same thing with Eo. It's pretty unconscious, actually. I started practicing and I noticed I did that, and thought "How strange! That's not supposed to happen!" But it's a hard habit to break.

KetchupSoldier:

witeowl:Here's my pronunciation key, as told to myself:

Pronounce the vowels like you did when learning German and Spanish. Oh, and stop dipthongizing them, you blasted American!

Done.

Hahahaha! Exactly!

I find I actually speak Esperanto with a bit of a Spanish/Rio accent, which is weird, because I've studied neither Spanish nor Portuguese.

My mother grew up in Brazil, so when I hear her speaking Portuguese with our house cleaners, she makes the "O" at the ends of words sound like "oo". So now I do the same thing with Eo. It's pretty unconscious, actually. I started practicing and I noticed I did that, and thought "How strange! That's not supposed to happen!" But it's a hard habit to break.

Don't go listening to Kurso de Esperanto if you want to break the habit