1. Ask an assistant for something directly behind you.
2. Ask the same assistant for something they clearly don't sell.
3. Take a newspaper and start doing the crossword.
4. Ask if you can just take the bit that's extra free, and leave the rest.
5. Always pay by cheque, especially if only buying a can of beans.
6. Wait till everything's gone through the till, and say 'shit - i've forgotten the carrots - I'll just go and get them.'
7. Wait till the assistant asks you before even thinking about looking  for your wallet.
8.Leave trolleys in the middle of aisles.
9. Bring a screaming toddler along, and do a big weekly shop.
10. 'Accidentally' knock over the delightful display that the shelf-stacker has been carefully and diligently arranging for over an hour.