Fifteen minute fix:
Sort out any loose papers, magazines, etc that are on / around your desk and file them. If yours have built up quite as much as mine, you might have to stop wherever you get to after 15 minutes!
I sometimes find it helps to create a folder for papers that needed to be
acted on within the next few days, and to roughly sort everything that can just be filed (e.g. finance-related in one pile, magazines in another pile, child-related in a third...)
Thirty minute fix:
Tidy out any drawers or bookshelves near your desk. If you tend to have reference books piled up on your desk, clear part of a shelf to hold them and just keep out the one(s) you're actually going to refer to on
a very frequent basis.
Do the same with stationary: you probably don't need a hole-puncher or stapler on your desk, for instance.
I'd love to see your "before" and "after" photos too! Feel free to email them to me, or -- even better -- you can share them on the Aliventures Facebook page. Let us know how much time you spent and how it felt afterwards.
:-)