Development and maintenance of complex web interfaces containing hundreds of input fields typically causes huge development effort. Changing the layout or adding input fields to complex user interfaces are especially tedious tasks are, because these changes affect the alignment of many other interface elements. To reduce this effort, we developed a ruler guide-based approach that combines the efficiency of automatic generation of complex user interfaces from an XML-based specification with the flexibility of a manually layouted user interface. First experiences with a proof-of-concept implementation show that the effort needed for development and maintenance can be significantly reduced.