Relation of the Asian session to the London session...

Could anyone share any thoughts or advice regarding the relation between the different sessions...

For example, is there anything in particular you look for in the overnight charts to help prepare for the day's action before London kicks off?

Any clues as to what madness may lie ahead for the day?

The terror plot was uncovered around GMT+2, when Asian session was still active. However, most of the gbp movement occured way past asian session.
The terror plot seems to have been fully contained though.

No steam left?

Generally, the Asian session stays quiet, even for the asian currencies. You're better off to dedicate more of your time towards the London open. Every now and then there's something worthwhile happening in the Asian session, but it's either happening right after NY's close, or right before London's open, so there's quite a bit of dead space in there.

yes, like that big EURUSD short candle on Aug 8th, 23:00 GMT... I think it was 23:00 GMT... anyhow, it surprised me that the move was in the asian session.

If I can remember correctly, tokyo wasn't open yet but sydney was.