Gargling with warm vinegar salt water is great!
I get good results from Egyptian licorice tea.
Slippery elm tea. It is the active ingredient in throat coat tea and thyers
Celestial Seasonings makes a Throat Soothers tea that I really like. Professional singers ofter use Throat Coat tea, but I've never tried it.
A college friend of mine, who is Macedonian, had her parents whip up a traditional cold remedy for me once and it was quite effective (okay this was over 30 years ago, but I'll never forget it). In a cup of black tea add the juice of one whole lemon, 1 tsp honey, several shakes of black pepper and one shot of whisky. YMMV!
Also, correct use of your vocal instrument helps prevent issues. Breathing with your diaphram, not straining your vocal chords. If your gonna sing like Roger Daltry, well, good luck NOT straining them!