this may sound basic, and some of you may groan - what the heck.
If you're mounting a cyclocomputer magnet on the front spoke, make sure you put it on one of the two spokes opposite to the air valve. Kinda balances out the wheel a bit. Its a minor mod, but I seen a couple of bikes where this wasn't so.
Here's an example of a wrong mount :
Please don't throw eggs at me for this !!