No, it won't ensure you don't catch covid-19, but some face coverage is better than none when making a trip out of the house. Tora Smart's a how-to vid walks us through a quick and easy way to create a face mask with materials you already have at hand:
"Let’s all make our own masks and let front line health workers get first dibs on the real ones. If we all wear our own when we leave the house, there will be less spread. New information is revealing that some face coverage is better than no face coverage. BUT, please allow care workers to get the real ones first!"