Old Navy has the best 100% cotton basic oversized tees! They're on sale for $15 and some colors are as low as $5.99! They come in 18 colors. I love to wear these with leggings and layer under most of my jackets or vests. Since they're already oversized, I go with a medium. If I want more length, I'd do a large. LTKMidsize LTKFindsUnder50 LTKSaleAlert