Can we get a sticky on hum/buzz troubleshooting?

[MovinTarget]

Just finished my very first build and drove myself near-insane trying to figure out why i was dead quiet UNTIL I started playing and then there was suddenly a bad, ungrounded-type hum... almost like distortion unless I grounded the bass by touching the bridge.

Turns out it wasn't the bass OR the amp, but the outlet my house! I tried upstairs and its great!

So I had this thought that it might be a good idea to list in one place all the things that *could* cause noise... and any tell-tale tricks to identifying that particular cause.

The ones I know are:
Ground loops
Bad joins
Single coils hum (not much we can about this one)
Environmental- lighting, poor power conditioning etc

More?

 

[Killed_by_Death]

Whenever a troubleshooting noise issue comes up there are generally 3 camps. The guys who have some experience fighting the problem, those who pontificate w/o any experience, those who really know the answers but the answers might go over a layman's head.
They're not clearly defined, since once in awhile a person will post that really knows & also has experience, but those occasions are rare.

 

[MovinTarget]

Understood, I guess I'm thinking there is some way to come up with a way to categorize the symptoms with some simple questions to help us that are less initiated to figure out where to start looking. Not an end all/be all guide.