Open the image you wish to use. As you can see from my image, it has LOADS of white to it.
Select your "Magic Wand" from your toolbar.
A box in your upper toolbar will pop up and looks like this:
Left click ONCE inside of the white area and you'll get this:
Hit the "Delete" button on your keyboard and you'll get this:
A closer look, though, reveals we have another problem: it took out all the white, but also some of her hair. Oops, I don't think she was looking for a new haircut!
So, here's where "Tolerance" comes in. We'll need to adjust it so that it takes out the white background, but leaves in her pretty long hair.
NOTE: To increase tolerance, slide the blue bar to the right.
Let's see how we did. Add a new layer in your layers box, flood fill white and then move white background to under your image.
When I do this, I noticed a few mars on my tube that need to be fixed. This would mean I'd have to lower my tolerance until it smooths SOME (if not all) of the blemishes/
This is what I achieved after tweaking my tolerance level to 28%:
You can still see jagged edges around the heart itself, and that can be easily taken care of if you find the right tolerance level that would safely take out all of the white. Play with yours and see what happens!