I have an outfit involving sweatpants that I think looks great for every day wear, and I learned it from observing it on a friend. Black spandex-type sweatpants (not tight, but not baggy, I think of them as "low profile"), a longer length polo shirt in an interesting color, untucked to cover my most unflattering features, and plain black flats. These are not expensive pieces, you can find all of these items at a place like Target.
I'm not saying everyone should wear this outfit. I'm just saying it is not that difficult to find things that look good, are easy to pull on, and are not expensive.