The following tip might not apply to all cable box DVRs, but try it on yours and, if it does, you'll be glad you did. It makes no sense to watch any show live given the ability to record it on DVR and skip the commercials. Even if you want to see a show when first broadcast, recording it by DVR and then waiting 15 minutes or so to start watching will let you skip the commercials and get to the end of the show just about when it ends in real-time. Now, here's the tip: Let's say it's 20 minutes after the hour and you just realized there's a show on you wanted to see. Rather than slap your head thinking you've missed 20 minutes, just highlight the show on your Guide Schedule, and hit record: Shzam, like magic, it will record from the actual beginning of the show.
[Note 1: We acknowledge and thank our crack audio/visual lab of professional television watchers for this discovery]
[Note 2: To skip commercials, of course, you also can just watch live and pause. But that runs certain risks such as having to take a telephone call that runs unduly long so the pause expires. In any event, if your record even as you watch live, that risk is eliminated]