mounting heatsink / waterblock - motherboard mounting holes

When making your own waterblock or heatsink, what do you do about mounting hardware? Ordinary bolts, or do you need the spring things? Where do you get the spring things? How tight do they need to be? Anything else that anyone might like to know about using the motherboard mounting holes?

When I made a waterblock, I cut out a piece of cardboard the size of the wb. I then traced the mobo mounting holes onto the cardboard then onto the copper block for drilling. As for the hardware, you should be able to buy the bolts, springs, rubber/nylon washers, and nuts from a local hardware store or home depot/lowes.

So how much pressure do I want on the springs/bolts, or how much torque to apply to the bolt? Rough estimates? I don't want to overtighten and hurt my cpu, and I don't want to undertighten and have poor thermal transfer.