[Pros] Easy to attach. Inexpensive. [Cons] Cannot provide mechanical attachment for heavier heat sinks or for high vibration environments. Surface must be cleaned for optimal adhesion. Moderate to low thermal conductivity. [Cost] Very low [Method] 
Thermal tape
T h e r m a l t a p e
E p o x y
W i r e f o r m Z - c l i p s
C l i p - o n
P u s h p i n w i t h c o m p r e s s i o n s p r i n g s
S t a n d - o f f s w i t h c o m p r e s s i o n s p r i n g s