I have previously written about ways to manipulate images on a budget so that graphics that are perhaps not all uniform looking can look more like they belong together. Recently I stumbled upon another fun (and free!) tool for editing images, vintageJS, which quickly and easily gives photos a vintage feeling with adjustable settings. It is similar to popular smartphone apps like Hipstamatic andInstagram, but geared for the desktop set.
For example, I did a Google Image search for images that were marked for commercial reuse with modification (click the link to learn how to do that if you don't already know) using the keyword school. I pulled the following images:
They aren't the greatest photos or particularly cohesive, but hey, maybe I'm trying to put together a little something on nationwide education and I'm a) in a hurry and b) on a budget of zero dollars. In less than 3 minutes I was able to upload them into vintageJS, adjust some settings, and Pow! Now I have this:
Not bad, eh?
***
AJ teaches a live, 3-hour class that offers tips/tricks for improving the look and feel of your PowerPoint presentations: Slide Sprucing: Remodeling Lackluster PowerPoint Slides for eLearning and Presentations.

These sites are really helpful for the Photoshop learner.
Fotoclipping.com
These sites are really helpful for the Photoshop learner.
Fotoclipping.com
These sites are really helpful for the Photoshop learner.
Fotoclipping.com