The idioms "to go up in smoke" and "to go up in flames" are very similar. They both mean burning and getting destroyed by fire. But if we use them to talk about failure, aren't there any nuances to remember? Aren't there any shades of meaning that differ?
Although these are both fire metaphors, they are not quite the same thing.
To "go up in smoke" means to disappear, dissipate, fail, or be destroyed as if by burning. A similar idiom would be to be "all for naught".
To "go up in flames" similarly means to burn, but usually more spectacularly, as if in a conflagration or other disaster. A similar idiom would be to "go down in flames" as in "crash and burn".
The first implies wasted or futile effort. The second implies spectacular failure.
My lifelong dream to become a doctor went up in smoke when I found out I would faint at the sight of blood.
My long-term plan to become a doctor went up in flames when, as a college prank, my friends and I stole the yacht of what turned out to be the director of the medical school.
Because there is some overlap in these definitions, in many situations you can use either.
1I’d love to see you revamp your second example. It leaves me wondering: isn’t there some way that one’s plans might go up in flames (instead of up in smoke) without any literal fire?– J.R. ♦Aug 22, 2018 at 9:21
2@J.R. If something goes up in smoke, then it leaves no trace. If something goes in up flames then it's leaves lasting damage. An example for the second that doesn't involve literal flames would be "My plan to become a famous doctor went up in flames when I killed the president"– UKMonkeyAug 22, 2018 at 10:54
@J.R. yeah, me too. I thought it was a bit hokey, but all the other options I came up with went to weird places. Anyway, edited :)– AndrewAug 22, 2018 at 11:37
I guess the nuance is related to the expression "vanish in a puff of smoke" (i.e. to disappear completely). This sense feeds "go up in smoke" as much as the fire metaphor does. Aug 22, 2018 at 11:39
1@Andrew - Based on your subtle distinction, I'll tell you which ones went through my mind: My lifelong dream to become a doctor went up in smoke after I failed my clinical exams for the third time in three years vs. My lifelong dream to become a doctor went up in flames after I flunked four of my first five courses in premed.– J.R. ♦Aug 22, 2018 at 13:49