I love this book and the philosophy, though I find it difficult to truly adopt the method with a very non minimalistic husband, two young kids, and two dogs. Those are probably just excuses though. Anyway, every once in a while I'll do a big purge of some section of the house. I wish I could do the whole house but it's not realistic right now. Getting rid of stuff, streamlining, truly thinking about what I need and don't need or what I love or don't love really does lead to not only a more productive lifestyle but a very nice sense of calm, at least for me. Literally less "things" to worry about, which clears up your brainpower to deal with the truly important aspects of life.
But, as far as tips go... don't have children? Haha, I'm joking =). But really, it's hard to maintain minimalism with kids (but if you do have kids or plan on having kids Simplicity Parenting is a good book along these lines). The only thing I can say as far as advice goes is you're doing a good thing. Stick with it and remind yourself every once in a while what the purpose of your belongings is. I've fallen off the path a bit and am sitting here thinking how nice it would be if I stuck (more or less) to the philosophy since reading the book some 5 years back. I would have more money, be less stressed, more productive, and happier I think. This makes me sound like I'm super unhappy, which I'm not. Just saying, in retrospect you always know better than your past self going through life =D.