One of my favorite locally-owned buiness is "The Chocolate Therapist", located right in the heart of Downtown Littleton. The owner makes "healthy chocolate" and is happy to explain why it's considered healthy. She also teaches classes and has wine and chocolate pairing nights. Her chocolate is divine!
There are not as many clothing boutiques as I would like to see in Downtown Littleton, but one that comes to mind is "Detai!s Boutique". In addition to clothing, they offer a wide variety of bath and body items.
Reinke Brothers Costume and Haunted Mansion is a costume shop along with a haunted house. The Reinke brothers grew up in Littleton and are a large part of the community. Their Turkey Leg and Wine Hoedown is fun and they also treat the ladies extra special during the annual "bracelet tour".
"Natural Surroundings" and "Seasons" are nice shops, as is "Kate's Wine Bar" and "Lola's Sugar Rush."
While this is a franchise, I would recommend visiting "Savory Spice Shop". This is a great way to purchase only what you need and the employees here really know their spices, which are very fresh and delicious.
Downtown Littleton has a lot of antique and "craftsy" type store, plus a lot of dining opportunities. I wish they had more true boutiques.
Two of my favorite places to dine are Delizios (for their weekend brunch, their ice cream and desserts or for drinks) and The Melting Pot (for fondue and special occassions).