I've think I've tried every approach with Mackenzie and one day one might work and the next day it doesn't. Ive taken to doing my grocery shopping via the internet to eliminate the problem of not wanting to sit in a shopping trolly and having a major tantrum. I limit all other shopping to 1 hour and try and do it in the morning when she is happier. I think a lot of it is an age thing and we just have to ride it out in anyway that works for you both. Sorry, no great advice here.