Where should I put my thermal probes

[SnowPunk98]

I have 2 thermal probes that I am putting on the front bezel of my case and one is going to be for my CPU and the other is going to be for my video card. I have 2 questions. 1. Where should I put the probe on the video card to get the most accurate tempature readings of the GPU and 2. What should I use to attach and hold the probe to the video card and CPU? Also thermal probes are more accurate than the one built into a motherboard right