One thing that helps me when I remember to do it is a Gratitude list. Even if I can just be grateful for my house and air to breathe.
I just read a blog post about that yesterday if you can list 10 things you can really shift your mood and if you keep doing it even better. I used to keep a list with my oldest when he was younger we might start doing that again.
I don't know if that really helps clear out the clutter. It can help when I see myself spiraling down into the dark places. I think of FLYlady too and Finally Loving Yourself.
I could hang up sticky notes around the house too with positive messages to myself and reminders.
Looking forward to hearing other ideas too.