I like to keep the clutter bustings matter-of-fact. There's no blaming or should haves. There's clutter, and it's bothering the person, and let's see what we can do to let it go!
This helps because it keeps my clients open to what's in front of them. It keeps them in the present moment where they can actually do something about the situation.
I was working with a client recently who felt shut down in the midst of piles of various things in her bedroom. She saw all the stuff, blamed herself for getting in the situation, and felt there was nothing she could do to fix her predicament.
I said that the piles were just decisions waiting to be made, and let's go ahead and start making them. I sidestepped the reason they were there, or how long they'd been there, or how she was feeling. I knew she'd feel better once she started making decisions.
After a few minutes of asking about each thing, "Do I like and use this, or can I let it go?" she was out of her thinking mind and in the midst of her doing mind. She was making decisions, and the piles were going down.