One of the things we've found working with Oracle Portal is that the ability to slap down a page quickly leads to the ability to create some butt-ugly pages. Which inevitably means somebody has to come along later and clean it up. Some HTML house-keeping if you will.
One of the things I've found really useful is to create a couple extra regions at the bottom of a page, one for items and one for portlets. Then I move all the existing content from the rest of the page (using the List edit mode, not Graphical) into those extra regions. That leaves me free to delete/create/modify the rest of the page and then I can restore the content from those saved regions back into the cleaned up page.