For a sore throat or a hacking cough, I have a slightly different approach, though the Vitamin C tea is still a great place to start.
For these, I use a lot of peppermint candies - great for sore throat, cough, nausea in general.
Plain yogurt (unsweetened) with a swirl of raw honey is excellent for this situation. I only lick the spoon most of the time and it gives me relief. (Not as good on a phlemy cough though.)