I wanted to make a note of one of these things I keep forgetting in Adobe Illustrator. It is very simple, obvious and keeps me sane while drawing UI elements.
Make sure "Align to Pixel Grid" is actually selected!
That gets you out of so much trouble. Problem is, you need to keep an eye on the transform pane since this is a per-object setting. It is nog global to everything on your canvas.
Of-course the old-school technique of placing the strokes outside (or inside) the object bounds still works and can actually help you in transferring dimensions from the canvas into CSS (which puts borders "outside" when working correctly).
(I can't believe they still haven't fixed the rounding errors that randomly occur when drawing and moving objects around.)