One of my favourite Picmonkey effects is called Shiro. I set it just to see how my image would look.
It looks quite pretty, don't you think? If you would like to achieve this effect on your own images, I'm just about to show you.
Open your image on your editing software. I use Gimp, because it's so quick and easy to use.
You're going to want to head to the Brightness-Contrast option. For this image, I set the brightness to 10 and the contrast to -3. Basically, you just want to make the image lighter and with less contrast. Experiment and find the one you like best.
You could either do this step now or at the very end. Do it now if you feel like you know what you're doing, but you can always readjust if you don't like the final image.
Either way, you'll have to use the Curves tool. I dragged the highlights-counter past the lightest 'bulge' on the histogram to 164. This made the whole image pretty light. Like I said, you could leave this step til last if you like.
For this final step, you need to find the Colorize tool. Because I wanted this to be pretty vintage, I found a brown-ish hue that wasn't too yellow (18), and decreased the saturation right down to 16. Then just to finish I increased the lightness to 7, to lighten the darkness of the leotards and tights.
Here's the final image, and some others in the 'series'.
And there you go, how to get your own 'Shiro' effect from Picmonkey using Gimp! Enjoy :D