Remembering exact values of trig ratios

So in trigonometry, you have the unit circle with the different trig ratio values in radians like pi, pi/4, 3pi/2, etc. How does one remember that co pi/6 is equal to sqrt(3)/2? Is there an easy way to remember the placement of those on the unit circle so you know which quadrant they're in? And also is there a way to know each conversion of a measure in degrees to radians without using a calculator?

Basically I'm wondering any tips to make this whole process easier for the test so I don't have to calculate these things each time.