Arrange sections of the dialog box logically into rows or columns so users can scan them from left to right or from top to bottom. Align related entry fields (such as edit boxes or list boxes) both vertically and horizontally, so that when users switch fields by pressing Tab, the cursor moves in a straight, orthogonal line.
If there is a natural order for entering data—such as the X, Y, and Z of coordinates—order the fields in the same way. Align boxed areas both vertically and horizontally. Do not leave a lot of white space around or between boxed areas. Extend their width to the right, if necessary.