mount blocks or make completed loop first?

How do most people go about mounting up their watercooling gear? Do you mount the blocks on to the CPU/GPU/whatever first, then carefully measure and cut the tubing? Or do you create the whole loop after measuring and then mount the blocks once they have tubing attached?

With the frst option it seems to me like the block mounting could be disturbed a bit by having to force on the tubing, possibly messing up the TIM. With the latter there could be less than ideal tubing lengths, either long or short, or kinks. So both have their drawbacks, so I was wondering how most people install their loops?

Personally I have only mounted one block and I built the loop first. If I was to do it again I would mount the block first as mounting block and having to fight the tubing was a royal pain in the buttock.

Maybe what I'll do is mount the blocks dry without TIM or the intent to keep them on, measure and cut the tubing, then complete the loop and remount the blocks with TIM.

I see what you're saying about fighting the tubing though. hmhmm

ive built many WC systems and i mount everything first the do the tubing..

I'm the opposite. I loosely mount the block, set hose next to it and bend it to the other end barb, mark, then pull the block in question and cut the tube to length. There is way too much force with the way I do the tubes (uniquely pre-clamped), so I assemble it outside, then drop it in. I do the vid card free (not on the mobo) and then holding it by the block at first, slide it into place and screw it to the PCI bracket. I NEVER push or pull tube when the loop is mounted to a component, it's just too risky. All you need is force on one corner of a GPU core and CRACK, it's over.

I always mount the blocks & then add the tubing so there is neither too much or too little. If you have your blocks properly mounted, there should be no way you can crack a core due to the stronger mounted block pressure.
If the tubing does not slide fairly easy onto the barb, I use my heat gun to warm up the tubing so it will.