Provide advice on how to accomplish the following goal. Give ONLY the advice, no other words or explanation.
For example:

Answer: <advice, as short as possible; a single sentence!>.

Goal: Sew a simple plastic bag holder.
Get a piece of fabric and measure 20 inches long by 10 inches wide. Turn up and inch at the bottom and sew. Add elastic to size you want. Do the same at the top and add a loop for hanging. Add plastic bags.
Use a plastic bag and sew it shut, then add pockets with elastic.