Ive heard that the proper way (according to Arctic Silver website) is to apply and smooth out the paste on the heatsink (using your credit card, etc) and then just run a line (running up and down) of paste on the CPU itself and simply place the heatsink on and twist slightly as the heatsink will spread the paste out effectively on the CPU...
Remove any residue on processor with a lint-free cloth
Put a small dot of paste on the CPU itself.. Install heatsink.
Remove any residue on processor.. make the CPU IHS surface wet with a very slightly damp cloth to fill tiny imperfections and scratches.
Don't get ANY water in your processor...
Put a small dot of paste on the base of the heatsink and install.
just apply on one of the 2 surfaces?? the heatsink or CPU?
it doesn't make a difference. I personally use antec silver, very similar to artic silver. They state put a small spread on the HS and a tiny dot (less then a peace of rice) on the CPU. I've also done the spread on the CPU, pea size on the CPU, make an "X" on the CPU, and several others. All the temp reading where within 2C of each other. I personally like the X method.
Currently I have the CM 212+ cooler. I just placed a very thin line on each heat pipe and a rice size amount on the CPU. works fine.