H.264 encoding best practices

During my research I've developed a decent book knowledge of compression and encoding, but H.24 is such a settings beast of a codec I figured it might be good to have a best practices thread for those, like me, who don't great practical knowledge.

Specifically I'm compressing HD and SD footage for streaming quicktime movies and to play on a broadcast unit of which I have no specs for. I'm just running tons of quality tests. I got a really nice, playable quality, but noticed that every once in a while there are some digital artifacts or some playback quality issues... problem being that my files are an hour long at a time and I have 72 hours of programing, so its hard to watch every second... what are the best practices to strike a balance between quality and having confidence that I wont have digital glitches?