Double exposure photo with Gimp

Since I bought my first camera, I want to do a double exposure photo.

I know double exposure photos are two combined photos, like the following one:

_{(source: alexwisephotography.net)}

My goal is make one of these combining my face and fire.

Somebody knows how to do it in Gimp? I searched tutorials for this, but no tutorial about double exposure in Gimp was found.

Thanks!

Answer

Open both photos individually (ie in different windows/tabs).

Select all and copy one photo, then on the other photo "Paste as -> New layer"

This pastes one photo over the other. If the sizes don't match up, you can resize one layer at a time with Layer -> Scale layer. Resize the larger layer down. You can move a layer around with the move tool in the toolbar.

Now, in the layers window, select the top layer and choose a blend mode and opacity for the upper layer. The simplest blend mode is just to use "Normal" and adjust the opacity, but it may create a more interesting result to try the other blend modes, particularly modes such as "Multiply" or "Soft light". For each blend mode, try adjusting the opacity of the top layer too to see how that mode reacts to changes in opacity.