Choose a cardigan and navy dress pants for seriously dapper attire. After 30, you probably want to start dressing maturely. If that's the case, getups like this are a tested option.
Navy Dress Pants with Cardigan Smart Casual Warm Weather Outfits For Men In Their 30s
Consider wearing a cardigan and navy dress pants if you're going for a clean-cut, classic ensemble. Bring an easy-going feel to this outfit by sporting brown suede desert boots. This outfit demonstrates that after 30 your sartorial options are pretty much limitless.