20s: For most of us, our twenties are the time we're learning how to survive on our own, and oftentimes that means choosing between paying off student loans and being able to spruce up our winter wardrobe. But start grooming good buying habits now — even if the few products you buy are more expensive than what you were used to spending in your teens, with good research, these quality buys will last you well into your 30s. Look for basics in versatile cuts, accentuating shapes, and durable, long-lasting fabrics.

Cashmere sweater — Uniqlo's cashmere is super-affordable, as far as cashmere goes, and relatively long-lasting. These won't start pilling right away, but we suggest taking extra good care of them to extend the lifespan.
Uniqlo Cashmere Crew Neck, $69.90, available at Uniqlo.

T-shirt — T by Alexander Wang's T-shirts have the perfect blend of sheerness and slouch, making them the ideal shirt to wear for any occasion.
T By Alexander Wang Classic Tee, $98, available at My Theresa.

Jeans — rag & bone's classically cut denim will weather through a decade's worth of trends. Plus, coming in a ton of washes, designs, and patterns, you'll be able to find a pair that perfectly expresses your personality.
rag & bone Midrise Jean, $198, available at Intermix.