avoid白色散热膏

It's too thin. Once it drys up, it leaves gaps between CPU package and the heatsink.

I'd recommend Arctic Silver. Apply a thin layer on the top of CPU, spread it evenly with a spreader. As others suggested, try to keep the layer thin. The purpose of thermal paste to create a good contact between CPU and HSF. It fills the microscopic gaps on the surface of CPU and HSF. If the bottom surface of HSF looks really rough, you may have to sand it with very fine sand paper.

I always clean up the original thermal paste on a new HSF if it's white and re-apply arctic silver. By doing it properly, I can generally knock the CPU temp down by a few Celsius.