For a look that's very straightforward but can be modified in a myriad of different ways, consider pairing a black and white long sleeve shirt with a black long sleeve t-shirt.
White and Blue Low Top Sneakers with Long Sleeve T-Shirt Casual Summer Outfits For Men In Their 30s
The mix-and-match capabilities of a black long sleeve t-shirt and white chinos ensure you'll always have them on regular rotation. This look is finished off really well with a pair of white canvas low top sneakers.
This combo of a grey long sleeve t-shirt and olive cargo pants is on the casual side yet it's also stylish and really dapper. The whole ensemble comes together if you introduce a pair of white print canvas low top sneakers to your outfit.
Dress in a navy check blazer and charcoal wool chinos to assemble a proper and polished look. Send your outfit down a more informal path by finishing with a pair of white canvas low top sneakers.
This cool and casual look is really pared down: a grey long sleeve t-shirt and dark brown plaid chinos. Add white canvas low top sneakers to this outfit and the whole ensemble will come together.