For something more on the casual side, you can easily dress in a black overcoat and light blue skinny jeans. Complement this ensemble with low top sneakers to immediately amp up the wow factor of this ensemble. As you can see, this look is a really savvy choice, especially for awkward transition weather, when the temps are starting to drop. Casual looks for stylish 20-year-old guys aren't actually that hard, as you see here.