I find it fun to rock a lot of my dresses with a similar style. Adding a sneaker type shoe (like Converse's or Keds) takes the femininity of wearing a dress down a notch, but it's still playful. I wore a ring from my Remedy that played off of the magenta lining in the dress that's sometimes visible. Rings are an easy accessory to add without feeling like you're overdoing it.
A moto jacket is an amazing investment. It can be expensive if you get real leather, but you can always go faux (& be animal friendly). I get a lot of wear out of mine & it's perfect because it can dress up an outfit or make it boyish, all while keeping it chic. For me, it exudes a level of confidence since I can feel bad ass & feminine at the same time in one. I've seen really great ones sold at Urban Outfitters & even Victoria's Secret online. It's a must-have for me.