Potting Mix #1 for Mediterranean Herbs
2 Parts packaged potting soil
1 Part Perlite
1 Part Coir Or 1 Part Peat Moss (to improve drainage, aeration and some water retention)
If using peat moss add a bit of crushed limestone to counteract the Moss acidity. This is especially important for plants that don’t tolerate PH levels on the acid side. i.e. less than 7.0

Potting Mix #2 for Mediterranean Herbs
8 cups packaged potting soil
3 cups  Perlite = 35% of potting soil
2 Cups of Cactus mix to improve drainage more than just perlite.
Mix thoroughly by hand so you can feel the mixture as well as look at it to ensure the perlite is thoroughly mixed.

This mixture will make almost three quarters of a one gallon bag plastic bag. I currently keep a gallon of the mixture without any cactus mix and one with cactus mix. My Mediterranean Herbs are doing ok in both mixtures. But I think the 8 potting soil -3 cups Perlite and 2 cups cactus mix is best.

While all 4 of these soil recipes are good ones, adding mycorhizzae, a microscopic fungus, to your soil mix will vastly improve its effectiveness. Scientists discovered that mycorhizzae is a fungus found in the wild that improves a plants ability to use water and nutrients from the soil. The scientists and growers also found indoor plants were in desperate need of this fungus to achieve maximum growth, leaf structure and flavor. All of which are important in growing herbs. Check with your local nursery for potting soil mixes containing this necessary happy fungus.

Video How to Mix Potting Soil

http://www.yourindoorherbgarden.com/media/mixingpottingsoil33112/