Good advice from Runner! It's all a matter of personal preference and application methods.
I too, use pastel chalks with no adhesive (I mainly use the landscape box of 24 colors from Dick Blick).http://www.dickblick.com/products/blick ... rue#photos
Their earth-tones (set of 12) is another good choice.
Easy to use and correct, plus they are fairly inexpensive!
Practice is the key word here.