It's funny, everyone always says not to get the tiny clothes but you really just never know. We had very few things in 0-3mo, and nothing in newborn size, and our DD ended up being small. She was 6lbs 15oz at birth and came home at around 6lbs 10oz. The coming home outfit we'd brought to the hospital was 0-3mo size and it was ridiculously huge on her. Same with all the 0-3 sleepers. Our best friend went out & bought a few sleepers & onesies in newborn size just so the kid didn't have to look like a clown in giant clothes.She only wore the newborn things for a few weeks but I was glad we had them.
My coming home outfit was also too big for my baby...we ended up leaving her in the shirt the hospital puts the babies in. We ended up using the newborn size for at least a month.
And don't stock up too much on clothes...you never know if a certain brand will fit your baby properly. My daughter is 99% height, but only around 50% weight so a *lot* of brands look weird on her. Sleeves are short, but the stomach area has *way* too much extra cloth.