A designer you are in sync with should be able to make the same decision you would, even when you aren't there. Most people do not fix their own teeth or cut their own hair. They go to a professional who has experience and makes decisions like this every day. A designer will help you eliminiate costly mistakes and help you make a plan. Sometimes, you can even create a whole new look just by re-arranging the items you have - a good designer will see this and help you.