Make a note of everything you look at!

You've spent hours looking through some parish records without any luck. It's very, very easy to go on to the next search without making any notes about this - after all, you've found no information so there's nothing to write, right? No - a few months down the line you will find yourself experiencing deja'vu as you suddenly realise the records you have painstakingly searched for the last hour are the ones you looked at months ago. What a waste of time! Make sure you keep records of everything you've looked at even if it revealed nothing.