Clutter
Everybody has a system for reducing clutter. If you don't have your own system, you need one. The only system that works for you is the system you create. This is mine, which will constantly evolve.
Principles
buy a shallow inbox
that holds papers neatly
has sides so that if you put other things in it, those things won't fall out
do I need an outbox? Maybe, for things that are to go outside the house to people (gifts, mail, etc.)
everything has a place
once done using them, return that thing to that place immediately. If you can't do it immediately, put it in the inbox.
I suffer from 'out of sight, out of mind', so some things need to be visible otherwise I'll forget about them. Other things don't have that problem.
buy or construct a really good desk with drawers.
Little things
there's such a thing as too many containers. Containers mean the possibility of more stuff. There's also such a thing as too few. Everything has a place. Empty containers should be washed and recycled.
get nice-looking holders for things like pens & pencils and loose change.
periodically roll loose change and bring it back to the bank. I store pennies, nickels and dimes in an old cocoa tin (which looks nice) and roll them up when it gets full. (Quarters, loonies and toonies are for laundry and sometimes raiding.)
velcro cable ties look nicer than twist ties
need to decide what to do with all the twist ties I've accumulated over the years
multiple pairs of scissors is OK, but each one has a place
I need scissors in the office, but don't want to go to the kitchen to grab them, and vice versa.
Books
I love books, and can't let go of them, especially not unread ones
the principle, not yet fully put in practice, should be:
keep reference books that get used more than once a year. Pity that the Internet is so ubiquitous and informationful.
keep some books which have sentimental value, and which I'll read again (easy way to determine which books I'll read again are to look at the books I've already read more than once)
try to accept that if I paid full price for the book, and read the whole book, that I got full value out of the book, and that it's time to give someone else some value from it
sell as many books to the used book store for credit, not cash (since you usually get more)
donate the rest to the library. The library will do one of 3 things with them:
add them to their catalogue
sell them
recycle them
on my newly empty bookshelves, put nice things that remind you of the love you feel and receive from the outside world
Technology
periodically go through the technology shelf and ask if it's still useful
if it's useful, when's the last time I used it?
sell or donate stuff no longer going to use but might have value to someone you know
donate (to an ethical electronics recycler that you have personally visited the shop floor of) old technology.
I can vouch for http://freegeekvancouver.org/ which tries to take apart old electronics and salvages or sells that which is still useful, but don't just believe me. Get the tour and see for yourself.