The right flat boot can be the perfect transitional shoe from fall to spring and beyond: Wear this comfy, versatile shoe with everything from skirts (see Kate Bosworth), to shorts (see Rachel Bilson), to jeans (see Emma Roberts).

Here are 5 affordable flat boot picks to help get you started.

I apply the same rule one might apply to a stock portfolio as I do to my denim collection: Diversify! From my Charlotte Russe wide legs to my Habitual straight leg skinnies, I believe in investing in great jeans that fit, in a variety of styles, from a variety of brands. One of my all-time favorite denim brands is 7 For All Mankind, and right now you can score savings up to 75% off this premium denim brand over at eBay Fashion Vault.

You'll find cropped styles that will go great with heels for summer, wide-leg flares (like the popular Dojo, shown above) to get your '70s fix, as well as a stylish romper, a cool denim skirt and more. It's all happening at eBay Fashion Vault NOW through Fri. 4/22 9pm PT only.

Shown above from left: "Dojo" wide leg jeans, $99.99 (down from $215); Sequin top, $42.99 (down from $174); Romper, $47.99 (down from $189.00)

To celebrate Earth Week, Yes To Carrots, makers of natural hair and skin products featuring key ingredients such as carrots, blueberries, cucumber and tomatoes, will be offering 25% off ALL products site wide, beginning Monday, April 18th, through Sunday, April 24th!

Simply enter the promotion code EARTH when checking out.

This good-for-you company has also teamed up with Whole Foods to do great things for local communities. Click here to learn how Yes To's non-profit arm, the Yes To Seed Fund, is helping build school and community gardens in 2011.

Never tried Yes To? Check out our review of Yes to Carrots Lip Care line here.

Marc by Marc Jacobs' "Simon" Colorblock swimsuit is $142 at Zappos. Such a fun take on colorblocking for summer! But you can get a similar look for $92 less. See if you can spot the designer suit below. Click either image to check your guess!

The humble espadrille is now the height of chic, with designers like Kate Spade and Diane Von Furstenberg creating versions of this jute and cotton shoe. Celebrity fans such as Jennifer Garner and Kate Bosworth (shown above in Soludos espadrilles) provide some styling ideas: Pair them with preppy basics or playfully cool pieces for relaxed summer style.

Read on for 5 espadrille flats to suit every budget.