Why do some baby boy t-shirts have buttons on the shoulder?

The buttons on the shoulder are designed to widen the neckline so you can easily pull the shirt over his head. Because babies have proportionately larger heads, unfastening these snaps ensures the dressing process is smooth and doesn't stretch out the collar.

Should I buy sweaters a size larger so they fit over other shirts?

Yes, sizing up for winter sweaters is a great idea because it gives you plenty of room to layer bodyvests underneath. Just roll the cuffs up if the sleeves are too long so his hands remain free to play comfortably.

Do baby boy tank tops provide enough coverage in the summer?

Tank tops keep your baby cool, but they leave his shoulders and arms completely exposed to the sun. If he wears one outdoors, you must be diligent about applying baby-safe sunscreen to all his exposed skin to prevent sunburn.

Can I put a long-sleeve t-shirt under a short-sleeve top?

Yes, layering a snug long-sleeve shirt under a short-sleeve tee is a practical way to keep wearing summer styles into the autumn. Just make sure the long-sleeve base layer fits tightly so the fabrics don't bunch up uncomfortably under his arms.