You don't need to be a photograph editor or rush to any friend to make your photos better, Google+ has inbuild photograph editor, which can improve you photos from "GOOD" to "WOW". And you also not need to make account on other image hosting websites as Google+ has integrated Picasa web albums in Google+ and you can enjoy unlimited image storage online.
Select you picture you want to edit,
Click on the "Actions" button below the picture.
And Click " Edit Photo " Link
There are currently 6 options with which you can edit your picture but it is expected that Google will add more editing features. Select any of the effect, it will show on your picture, click Undo if you want to step back.
When complete, Hit Done editing, and you are done.