Use frames to group related information or graphics. Unify individual graphics in varying styles by placing them all in one frame or placing each item in separate but matching frames.
Use frames to set apart information. For example, set apart the fine print in an ad with a box near the bottom.
Use frames to emphasize. In a manual, draw attention to key points or hot tips with a frame. It indicates that this information is important.
There are other ways to group, set apart, and emphasize information including through font choices, color, position on the page, and alignment. Consider using those organizational methods in place of some or all frames, boxes, and borders to avoid that boxed in look.