A flip flop or latch is a circuit that has two stable states and can be used to store state information. They are fundamental building blocks of electronics system used in computers, communications and many other systems. This paper enumerates the low-power, high speed D-flip flop based on comparison between the various techniques i.e. double edge triggering flip flop, low swing double edge flip flop, multi threshold CMOS and conditional data mapping flip flop. In this paper, various designs are presented by connecting limited number of transistors and as the transistors used have small area and low power consumption, they can be used in buffers, registers, microprocessors, etc.