Command+Drag File Icons to Fit To Grid

When you drag file and folder icons on the Desktop, or in any Finder window where you are using icon view, they will snap to a grid if you have Snap To Grid turned on in View Options (Finder, View, Show View Options). But if you don’t use the grid normally, you can use it for just one drag by holding down the Command key and dragging. When you release the icons selected will snap to the nearest grid spot.