Here are a few interesting add-ins available online that can enhance your capabilities for working with drawn objects. Some are free; some are not.
Shape Styles. This add-in lets you create styles that apply formatting to drawn objects. The free version lets you save three styles; the pay version has no limit. www.rdpslides.com/pptoolS/FAQ00037
Smooth Shadows. Ever wanted to create a smooth gradient shadow behind a gradient-filled object? This add-in helps you with that. http://officeone.mvps.org/smooth-shadows/smooth-shadowsl
Find and Replace Colors. If you apply manual colors and fills to objects, and then want to search for and replace all instances of such formatting, use this add-in. www.mvps.org/skp/pptxp006
Shape Console. This add-in provides a floating window that shows the current selected shape(s). This is handy when you are trying to select one shape in a layered stack and you aren't sure when you've got it successfully. www.mvps.org/skp/sconsole