I've been decluttering a lot in the house. As I run across stuff I know that we will no longer use, no longer fits, isn't loved by anyone, is broken, and so forth, I've been finding ways to get rid of stuff.
I enjoy posting usable items with little to no monetary value on Freecycle (a Yahoo group available in most areas where people post offers or requests of usable items that are FREE), it's wonderful to have someone come pick up an item that they need or want and know that it is not going to end up in the landfill or just taking up space and energy in our home. Using Freecycle I have recently gotten my 5-year-olds Exersaucer that he used as an infant and that a friend of mine used for her daughter, who will be 4 this year, the Exersaucer has been in my garage for at least a couple of years if not longer. Just this past week I also I gave a loveseat to someone who just moved into a new place and had no furnishings and two wing chairs to a Wellness Center at a local high school.
Clothes and shoes that are still in good condition get bagged up and go to Goodwill. The Goodwill location I go to has a "drive-thru" donation area. Just drive up, open the trunk, unload the bags, get a receipt and drive away. No need to find parking and carry bags down the street. Another good place in San Francisco is Community Thrift Store on Valencia Street. You can designate a charity for proceeds of the sales of your donation to go to. I prefer Goodwill because of its convenience and their convenient hours.
Athletic shoes that are no longer in good condition go to Lombardi Sports because they participate in Nike's Reuse-A-Shoe program that recycles athletic shoes into reusable materials including safety materials for playgrounds in inner cities. Definitely better than throwing them away.
The easiest way is definitely to do this as I run across things. For example, when putting away laundry if I know a particular piece of clothing doesn't fit one of us then it goes into the donation bag that I keep in the closet. If it's my younger son's clothes then it goes into a separate bag for a friend who has a son younger than mine who can fit the clothes.
Not too long ago I was looking for the garlic press in one of the kitchen drawers and since I couldn't find it quickly I emptied out the drawer, finished preparing our dinner and while it finished cooking, I wiped out the drawer, put back only what I knew we needed to keep and let go of quite a few kitchen items that were not being used or we had too many of. How many kitchen tongs does someone really need? Definitely not 9 of them! At least we don't.
So, again the way I've found it to be most effective is to declutter as I run across things, every time I open a cupboard, a drawer or some other area do a quick perusal and see if there is anything that can be given away, donated or if it has to go to the trash and immediately put it in the designated area for donation, write a post for Freecycle or put in the garbage. Whenever possible donate or give away an item, no need to send it to the landfill if there is a possibility of someone else being able to use it.