Dryer heat shrinks the f'ck out of cotton. Just to make it simple I buy everything to be washed cold and tumble-dried low to avoid sorting or damaging laundry. I've ruined a couple of pieces along the way but screw hand-washing and drying flat. Woolite, cold water, gentle cycles and a little bit of Shout do a great job of cleaning and are easy on fabric. Heat fades color and alters/degrades materials. Shrinkage from extreme dryer heat can cause irrevocable harm when it occurs at different rates in the same piece. Over-drying a piece (even on low) can fuck it up. Hot wash/dry only for whites or to shrink cotton.
There is a lot off difference in piques which have a looser weave and tendency to shrink. I like the thicker, rougher piques have a solid drape and tend to shrink the least. Size up one and do a hot dry to tighten up the weave, thicken the material, and get that coarse duck-like fabric. Hmm...I need to start wearing more polos.