I've just started a spreadsheet, so thanks for that suggestion!
I have about 12 birth certificates for my Thomas Jones before I found the right one (turns out he wasn't Thomas Henry Jones, just plain Thomas Jones).
I am currently up to number six for his brother George and still haven't found him.
Umm ... you do know you can add in "reference checking" and that you could put in the names of the parents (if I'm doing that, I try to be fairly vague)?
You still pay, but if it doesn't match, then they will email you to say the certificate won't be produced because the field you specified doesn't match, and they'll refund you either £3 or £4 (I forget which).
That said, I'm up to four for Great Great-Aunt Florence (my avatar to the left). Not only did she upset the family we know not why, but she's incredibly elusive.