Tips for selecting and using a heat sink for high power LEDs. – Luxeon Star LEDs

Choose a heat sink with as large a cooling surface area as possible.

Do not confuse surface area with mass or weight. The mass of a heat sink will provide little cooling capacity. The better option is a finned or pin array heat sink. You can, of course, improve the cooling performance of a heat sink by adding forced air cooling, but the starting point is always as much dissipative surface area as possible.
For forced air cooling, finned heat sinks are the best choice. For static air cooling, pin array heat sinks are the better option.
Black anodized heat sinks will perform better than unfinished aluminum.
Whenever possible, mount the fins of the heat sink so they are facing up.
Be sure that the mounting surfaces between the LED and the heat sink are as clean and as flat as possible.
Use a Thermal Interface Material (TIM) with as low a °C/W rating as possible. Double-sided thermal tape is an excellent choice for most applications.

Note that we do not recommend mechanical fasteners for any of the LED modules that we offer. If you need to mount the LED module in an environment subjected to vibration, we recommend Arctic Silver epoxy adhesive.
If you are using double-sided thermal tape, apply as much pressure as possible to the LED and heat sink during assembly to ensure solid contact between the LED, tape and heat sink.