We purchased our tickets in advance and went aroun...

We purchased our tickets in advance and went around opening. No long lines that way, and we also saw the crown jewels first to avoid the lines that form later.

After an hour, the first yeomen warder tour was offered. Very entertaining, but it pulls a huge crowd. As much as I liked our guide, I ended up skipping due to time and dislike of crowds. But if the crowd wouldn't bother you, these guys are very witty and make the content enjoyable.

We only allowed ourselves 1hr 40 minutes for the Tower, and I'd say a full 2hrs is needed for the crown jewels and tour (if you're there when they open). Otherwise, more time would be very recommended. We were very happy to wake up early and avoid the lines, though.