For something on the relaxed side, you can opt for a grey fair isle crew-neck sweater and brown corduroy chinos.
Grey Crew-neck Sweater with Dark Brown Chinos Warm Weather Outfits In Their 30s
Opt for a charcoal crew-neck sweater and brown chinos for a dapper, relaxed casual outfit. For maximum effect, add a pair of dark brown suede chelsea boots to the mix.