One of the biggest thing that is often underestimated is the fact that if you drink plenty of fluids, you're ultimately flushing the sickness out of your body. Water, ginger-ale, the works... make sure to drink. Not only that, but by drinking more fluids, you're thinning out the mucus that is in your system to allow you to feel more comfortable, even with a long lasting, thick cold.
Plenty of rest can also do the trick. If you're tired, sit down, take a break and sleep as much as you can. You're allowing your body to work harder while you're asleep and not working against it when you're pushing yourself to do all of the things on your to-do list. This can actually make your cold last longer because your body is not given enough time to repair itself when you sleep.
Chicken soup is great for the mind, body and soul. Chicken soup is hot, tastes good and is able to make the mucus that is built up in your sinuses to free flow which is always a good thing when it comes to not being able to smell, breathe or taste. This is also a good way to absorb nutrients that your body needs to fight the cold.
Honey is natural and it can make a sore throat feel better but on top of that, did you know that it you can make your own cough medicine with it as well? You just mix honey and apple cider vinegar together, ¼ of each, shake together well and then take one tablespoon every four hours.
If you find that you have a cold that will not go away, even after a few weeks, you should consult your primary care physician.