My Aunt Margaret is a real live decorator with great style. She's been helpful when I've had to make a few big changes in my house-mainly paint colors and what to do with the den. Instead of stepping in and giving me rules and guidelines to follow, she helps me visualize what I want. She did this with paint colors and the den, but she does it with little things as well.
What I'm talking about is rigging things to test them out. For example, before I chose a height for some side tables a few years ago, she was stacked random things and put a huge tray on the top to help me test different heights. Instead of staring at a random spot and using to a measuring tape, she actually made a table to visualize it. It's a simple idea that has helped me with several things. I'm trying to get some more side tables made, so I recently used the same trick again.
I pulled the same trick again with curtains, because I have trouble with window treatments. A desire for beautiful materials + a fear of spending money = a paralyzed Meg. I rigged the curtains with clothespins and took some pictures. Looking at the length of the curtains and the pattern on my wall helped chip away at the fear I have at stepping towards an actual decision.
Very rarely can I make a decorating decision all in my head. Before I spend time and money on a change in my home, rigging the look first has helped me move forward.