The simplest way to make natural cough syrup is to boil your herb (or herbs) of choice in water. The resulting liquid is now an herbal tea which can be strained and taken on its own. If you want to make a syrup, however, you'll need to let the strained tea cool just a bit and then add honey to the mixture. The amount of honey you add will vary depending on the amount of tea you have, but the resulting mixture should be thick enough to coat the throat.
^ Akhondzadeh, S.; Noroozian, M.; Mohammadi, M.; Ohadinia, S.; Jamshidi, A. H.; Khani, M. (2003). "Salvia officinalis extract in the treatment of patients with mild to moderate Alzheimer's disease: A double blind, randomized and placebo-controlled trial". Journal of Clinical Pharmacy and Therapeutics. 28 (1): 53–9. doi:10.1046/j.1365-2710.2003.00463.x. PMID 12605619.
Lightly bruise the thyme, e.g. with a mortar and pestle, and then place in a mug. Cover with 8 ounces of boiling water, cover, and let it steep for 10-15 minutes. Add some lemon or honey to taste, and drink the whole thing. Repeat 2-3 times daily as needed. It’s absolutely delightful just before bedtime (unless you aren’t a fan of thyme. But drink some anyways.)
Rhodiola rosea is very popular with Russian astronauts and athletes due to its ability to enhance physical strength and endurance. Also, taking rhodiola will allow the body to use less oxygen on a cellular level. Besides its beneficial effects on the body, this herb is often used to keep the mind sharp and improve memory. It is now gaining popularity as a natural anti-depressant. Rhodiola is considered an adaptogen. This means that it helps protect the body from all types of stress.

​Lemon balm is another herb with a potent fragrance, rubbing the leaves releases a somewhat minty and lemony scent into the air. First used by the Greeks over 2000 years ago lemon balm has a long standing use in herbal medicine. Back then the Greeks as well as the Romans would infuse there wine with the lemon balm to relieve fevers. Today lemon balm is often paired with other herbs such as valerian and hops for sleep promotion and relaxation. Its gaining popularity as some what of a nootropic as well, some studies have shown it to improve learning, and memory recall too. So its no surprise that a lot of herbal practitioners are recommending lemon balm as a treatment to Alzheimer's.
Hi, just want to share what I know – use only raw honey! If it was boiled, or even warmed up above body temp – it loses all it’s goodness and becomes as good as regular sugar. If it is boiled – it actually becomes cancerogenic. If you buy honey locally just pay attention to the appearance – fresh honey will stay in liquid form only a couple of month after that is is crystallized. People often mix honey with sugary syrups to keep it looking runny and to make more volume for profit. Be aware! Honey is extremely good for you, but with dry cough – not sure. It actually does dry your throat more.

Teas are a great way to get the benefits of sage all you need to do is steep one teaspoon of sage in a cup of water for about 10 minutes. You can also make a pretty awesome sore throat reliever by combining sage and thyme. Take an ounce of both grind them, and cover them with 16 ounces of apple cider vinegar. Be sure to shake it periodically and let it sit for ten days before using.