Whilst I'm generally not a hoarder, I still occasionally like to have a proper clear out to make sure I'm not hanging onto anything I don't need. Usually starting with my slightly over full wardrobe as well as getting rid of any books, CDs or gadgets that I don't use/need.
I feel much more relaxed once I've decluttered, but it's not just the wardrobe and study that needs the occasional overhaul.
Overtime most people will accumulate various tins and sauces that get shoved to the back of the shelf and slide past their use by date unnoticed. My wonderful grandmother had butter from the world war II butter mountain still in her freezer in the eighties!
If you're not religious at having a good spring clean your cupboards could probably have some nasty surprises lurking at the back, so it might be time for a clear out.
Firstly get rid of anything passed it's use by date, then throw out anything that's in date but just isn't appealing to you so you'll probably never cook (or give to your flat mate/neighbour/dog). For oils, smell/taste and throw out at the slightest hint of rancidity, also make sure you're not storing them anywhere near a source of heat, eg. Next to your hob or in a cupboard next to your oven.
Do the same in your fridge, then empty it entirely and give it a good clean. Also check your freezer - dump anything that's been in there over a year, and see if it needs defrosting.
If you find your cupboards are now bare, stock up on some fresh goodies, and if you found you threw a lot of jars and sauces away make a note to only buy the smallest jars so you'll waste less next time you have a clear out.
I'm very anti waste, so for any none food items I make use of the following rather than putting them in the bin:
Clothes - if they're still in good nick, give to friends, if a bit worn put in the charity bins at the supermarket where you can also donate old shoes, bed linen and towels
Books/DVDs - very easy to sell second hand on amazon, or donate to your local library
Unwanted gifts - anything brand new is easily saleable on ebay, anything of low value or used can be given away on freecycle