If you'd like take your off-duty game up a notch, consider teaming a grey sweater vest with skinny jeans. Puzzled as to how to round off? Add a pair of grey suede low top sneakers to the equation to change things up a bit. As you're moving from your 20s to your 30s, you want to start dressing like an adult. If that's the case, combos like this become very relevant.