Currently on my 3rd day of cold and it's almost completely gone.

On the very first day of symptoms (itchy throat, headache, runny nose, etc.) IMMEDIATELY get yourself an over the counter oral antiseptic (I prefer Bactidol) and gargle your entire mouth and throat thoroughly. Do this at least once a day, I prefer before bed/after breakfast. It kinda stings at first and your entire tongue would feel numb for the next 30mins but it's completely worth it. The phlegm would be instantly gone for a while and your throat would feel amazing. Repeat along with proper medications and you'll feel better in no time.

Only started doing this 2 years ago and I wish I would've done it earlier. My colds would literally go on for 2-3 weeks back then but it lasts for less than a week nowadays.