My twin sister, Julia, is in the midst of setting up her own business, a custom illustration service called Drawn for You. She’s always had a knack for making charming, funny, and true-to-life drawings of her friends and our family, and after her personalized greeting cards started to earn a following, she decided to make a go of it professionally.I’ve been full of encouragement, not only because I know how happy it makes her to create art for people but also because I recognize she’s on to a savvy business idea—borrowed straight from the pages of trend forecasters and future-thinking marketing consultants. But don’t just take my word for it.“Customization and personalization rank among the millennial generation’s most sought-after attributes” is one of the takeaways in senior editor (and resident futurist) Emili Vesilind’s enlightening feature “Great Retail Expectati