There's really no wrong or right way to apply thermal paste on your CPU and the topic is still heavily debated. There are some basic rules to follow however. First of all, concerning thermal paste "less is more". Whatever method you're using , please refrain from applying too much paste. And second don't use prepackaged thermal grease. Don't get us wrong, it will get the job done, much like your prepackaged heatsink from Intel or AMD. However, there's a reason the third party heatsink market is so prevalent today. And it's simply because they do a much much better job of cooling your CPU, especially during heavy CPU load or when overclocking. Since you've already decided to get a new heatsink you might as well spend the extra $7-10 for a decent thermal paste.

The main reason for applying thermal grease is to to fill any potential air pockets/gaps created by the uneven surface of the heatsink and CPU. Since air is less efficient at conducting heat, the goal is to eliminate as many as possible. Keep in mind that the air gaps are microscopic in nature.

To start things of you'll need to decide on what paste to get. In our case we will use "Arctic Silver 5". This paste is cheap, highly effective and not to mention used by pretty much the entire overclocking community.

You will also need to decide on a method of spreading the paste, as well as application area, whether it'd be the CPU or the heastsink. As far as method goes there are two popular ways. The first is to use a hard plastic card, (credit card). Second option is to spread the grease with your finger inside a thin plastic bag of sorts, (inside-out ziplock bag).

When choosing application area, we always spread the paste over the CPU, other may choose to spread it over the heatsink. Again, there is no right or wrong option here as long as you cover the chip which is located in the center of the CPU heat spreader.

          

Arctic cooling has posted their own guides, which differ slightly from ours. Instead of covering the whole heatspreader area, they recommend applying a small amount of paste at the center (for dual cores). Either way is fine, however if you decide on covering the whole area, be sure the paste does not flow over the edges of the heatspreader.

Start by applying a small amount of grease over the center and along the edges of the CPU heatspreader. Please remember to only work with the tiniest amount of paste. To easier illustrate the application process in our pictures we've used more paste then recommended.

Proceed, by taking a plastic card and start spreading the paste over the heatspreader surface.

The goal is to create as thin of a layer as possible. Hence as you are spreading the paste, use a paper towel, preferably a lint free cloth, to wipe of the card every so often, as if though you were trying to scrape of the paste from the heatspreader surface.

Finally, once you are satisfied with your layer, plug the CPU into the socket and attached the heatsink. Twist the heatsink 1-2 degrees clockwise and then couther clockwise to eliminate formation of air bubbles then secure the heatsink per heatsink instructions.

It's quite a simple process and it should help you drop the temperature of your CPU.