One of the best ways for a man to style such a practical piece as a v-neck t-shirt is to wear it with dress pants. If you're worried about dressing maturely, this outfit is a fail-safe option.
V-neck T-shirt with Dress Pants Hot Weather Outfits For Men In Their 30s
For an ensemble that's very straightforward but can be dressed up or down in a multitude of different ways, wear a v-neck t-shirt and dress pants. Definitely a smart choice when it comes to style for 30-something gents.