Beige has a minimum of three undertones already and that's just the beginning!  Let's say you pick a beige with a green undertone and your wall-to-wall beige carpeting has a red undertone, that beige will make the carpet look even more pink than it already is.  To ensure the right beige is selected, a professional will consider all the layers of beige that already exist in your home.

A limited budget means you have no budget to waste on mistakes.  The most common mistake I've seen is when decorating decisions are made on a piece-by-piece or room-by-room basis without considering the entire picture.  For example, a client was buying a new insert for her living room fireplace.  She was thinking the contemporary looking gray-steel option would be the best one until I pointed out her black tiled hearth and suggested a simple black one to match.  Her husband said, "Great, that's $500 less!"

Installing a $100 per square ft. mosaic backsplash into an 80's kitchen will have your backsplash look like today, and your kitchen look even more like yesterday.  Getting a professional opinion in advance will help you pick compatible finishes and find something closer to the era of the kitchen that may only cost $8 per square ft.  Sometimes it makes sense to move forward with a new design and sometimes you just have to work with what you have in order to achieve a final result you will enjoy.