When you go to the market next, take your reusable shopping bag - but take these bags too! We fill our reusable shopping bags with smaller plastic bags or paper bags (maybe re-use a few times then throw away).
With the exception of access to a sewing machine all the materials are cheap and easy to find - you may already have most of what you need. Look to things you have left over to use first.
4 years ago I started shopping at the local market and made my own shopping bags to re-use. But I found that I was still filling up this bag with lots of smaller disposable plastic and paper bags! I bought some netting fabric and made my first bags for weighing my fruit and veg. And I've been using them ever since. Since no one else noticed, I decided it was time to spread the word and get more people interested so I started making them to sell on my website www.onestringbag.com and now open sourcing how to make them to encourage others to do the same!