Choosing the wrong fabric for a project or worse using a really cheap quality fabric because it was a bargain… we have all done it. But it can really cause you problems.
Learn to avoid low-quality fabrics & you will be happier!
Think of texture, weight, weave (loose, tight, knit etc), pattern direction/pattern size, washability and if it is natural or synthetic.
Remember plain fabrics show up sewing imperfections that a pattern may hide.