Sorry I know this has been done to death but....

[way2serious]

Where is the best high street shop to be measured for a bra?

It's best to measure yourself- there have been loads of threads about this and there was a link to a site- maybe have a search?

I can recommend John Lewis

And measure your self and call for statisticallychallenged
She will give you the size and then you will know if the shop fitted you right.

I'm about to measure myself. Anyone got the instructions?

thebetterbracampaign.blogspot.co.uk/p/fitting-advice.html?m=1

Think this is the right one