Originally Posted by horriblyjollyjinx
just get a slim fitting white QUALITY shirt with a collar that is a little smaller than usual and wear it by itself. never ever ever wear a tee under a shirt, thats my opinion.
rolling up the sleeves cna look good if you do it right.
I generally agree with HJJ's comments. I think that the best look for a white shirt is alone, slim fitting, and with the collar either a little smaller than usual (think Helmut Lang or Dior Homme) or slightly larger, straight or semispread collar (think Prada, Jil Sander, or Barba.) IMO, Obedient Sons made the best shirt of this type (with a detachable collar) last F/W season. Terrific fabric, great, slim cut. Really nice collar shape. Retailed at around $200. I know that Stel's in Boston had them, and may be willing to dig them out of storage for you if you ask nicely. No guarantees though.
The casual, unironed, look that you are going for is better served by other types of shirts. I think that for layering, in general, a shirt in a heavier fabric or with a discreet pattern works better. MY favorite are some moleskin snap button Jil Sander shirts from the pre-Prada days (I have one in burnt orange, another in brown, both going threadbare from use), but military shirts (DSquared, though usually highly overpriced, has made some good ones in the past) and vintage western shirts work well.