The sextile is the 60 degree aspect. It is considered benefic, along with the trine. At 60 degrees the simplest way to pick out a sextile is to see it as every other sign, one sixth of a circle, or half a trine (120 degrees, one third a circle). The trine is an aspect of ease, the sextile one of opportunity. Signs in sextile, and planets in sextile, are complimentary, different in nature but pairing well. Trines are apples and oranges, peas and carrots. Sextiles are apples and cheese, peanut butter and chocolate.
Take, for example, a planet in Pisces sextiling a planet in Capricorn. Pisces can be grounded by Capricorn. Capricorn may be lightened by Pisces. Capricorn can put Pisces dreams into reality through work and tenacity. Pisces may connect Capricorn to the ethereal. A trine is easy; a sextile requires blending to access its benefits.
Do you have sextiles in your chart?