The first in an occasional series containing tiny but valuable nuggets of wisdom. Forgive me if you know this already, but many people don't.
If you are replacing old fasteners with stainless (which many people do), then it is crucial that you dab a bit of Copaslip onto the threads before fitting into alloy. If not, it is very likely that the two metals will react and over time the bolt or screw will seize solid (and I mean SOLID). I have just spent 4 hours extracting a number of such bolts and two of them only just came out. It's also well worth investing in a set of taps and running them through any threads that are dirty or suspect.
The above advice is far easier and less stressful than the sickening feeling of looking at a rounded/seized/broken fastener and realising that you'll have to take the engine out to stand a chance of removal (don't ask me how I know this, but in my defence it was some time ago and it's never happened since!).