The only time I downshift is when I know the light will be changing, and want to get a jump on it. Downshift into 2nd or 3rd, leave the clutch down, then let off and hit the gas when the light changes. Otherwise, Just leave it in neutral.

Even those that have to keep the revs up to keep it from stalling, just hold lightly on the gas to keep it revved in neutral, while stopping. When my Prelude had a bad carb that's what I had to do.

Or you COULD consider fixing the problem.