Yep, today was the day.
I'd made my appointment, I'd had loads of advice from lovely etsians http://www.etsy.com/forums_thread.php?thread_id=5693412 , I'd packed (and repacked!) my selection from my inventory (with the rest in the car just in case) and I was wearing my crochet spiral earrings.
Sadly the farm shop manager said that although they did carry quite a few crafts, it just didn't sell - but I was very welcome to set up a stall when they have their next open day (when there are always loads of families)
So - no massive order for knitted oast houses and piglets, but a real confidence boost. I know now that I CAN approach shops with confidence. The lovely girl serving in the shop even remembered one of my items pictured on the business card I left last week (which confirms my card "works") and was very impressed with the item when I showed it to her "in the flesh".
Yay me :-D