You know who she is and what she’ll be wearing to the holiday party. Aunt Lulu will be aglow in her busy-pattern sweater festooned with reindeer, snowmen and sequin-speckled snowflakes. If you photograph her on a busy background, the end result will be a visual mess. My advice: Pull Aunt Lulu to the nearest blank white wall and make your picture there. It worked for Avedon, it’ll work for you.