Part of simplifying life means keeping up your property boundaries: just because the thrift store has a fabulous collection of Hello Kitty collectibles doesn't mean that you need to buy them all. It's a good deal - but maybe it's someone else's good deal, not yours. That means thinking about what comes into your home. Enforce your boundaries with yourself.
Before that becomes your focus, however, you've got to conquer the excess you already have. Odds are, if you're new to simplicity you've got lots of stuff. Lots.
The collection of surplus material goods has, unfortunately, become The American Way.
Stuff means maintenance, even if it's just storing it in the backroom closet. Simple living is clean, efficient: if you have stuff stored in the backroom closet, it's for a reason and it serves a purpose. No? It needs to go.
Simplifying Your Stuff: the Courage to Toss
There are reasons you keep this stuff, and avoid culling. Some have gone so far as delineating between different "personalities" - dividing folk by motivation: procrastination, sentimentality, perfectionism. Whatever your hurdle, jump it - it takes courage to change the way you think, and the way you live.
Stripping Away the Excess
You're changing your world by reorganizing your environment: these things take time, be patient with yourself. Task by task, step by step, you'll get it all done.
Start with a room, or a section of a room. Take your laundry baskets (see How to Clean 1) and begin sorting. Give yourself a time limit. You can be sentimental later, you're just sorting right now. Fill the baskets: keep, toss, give, put-away.
When they are full, toss the toss pile first. Don't reevaluate your decisions here. Same for the give pile: put it in bags, label them for charity, and put them in the trunk of the car, or outside the door for pick up. Get them out of sight, it will keep everyone from rummaging through them later.
Take the put-away stuff and put this stuff up. Where it should be, in a perfect world. Not in another pile, in another room. Keep gets stored.
Now, check your time. If you've got it, do another round. If not, that's okay. You'll get there. This is part of the simple life, right now: these simple steps will get you where you need to be. Drop that pressure, don't stress over this. Keep it simple as you're simplifying.
For other methods on simplifying your stuff, see: organizedhome.com, thenewhomemaker.com.