It is good to see that so many of us do use our own bags. If you haven't heard of morsbags, do look on morsbags.com or google morsbags. A young woman who lives on a canal was so distressed by all the plastic bags floating by, and also damaging animals elsewhere, that she designed a very simple pattern for making your own bag, using old materials like duvet covers, curtains, skirts - just recycling an old/unused item into a shopping bag. There are now groups all over the world making these morsbags - for personal use, or giving away free. Making these bags is rather addictive - I now have loads - and they pop in the washing machine so stay hygienic too!
The packaging is a huge problem that is harder to tackle; fruit and veg are easy to buy loose, but not much else.