Lube your nuts and bolts. No, really.
Because David mentioned it. Here we go.
Back in school, a fastener engineer came in and lectured for an hour on fastener usage and operation. Amazingly enough, he didn't really repeat himself, there was a lot of information packed into that hour.
The difference between 'wet' and 'dry' bolts is actually quite amazing. Unless otherwise specified, most all torque specs are for dry fasteners. Clean with no oil or residue. The problem is when you apply a dry torque setting to a wet bolt. You will over torque it. Over tightening a bolt is just as bad as under tightening it. 20ft-lbs over is just as bad as 20 under, both will cause premature failure.
Its not super important on non-essential things like lug nuts and battery hold downs, but on engine components its much more important.
Even rubbing a bolt across your nose twice is enough to properly lubricate it (as long as you dont have dry skin)
When you put the new bolts in, either clean the threads well, or reduce the torque specs by 15-20% for oil. 50% for teflon based lubricants. Otherwise the chance of failure is greatly increased.