It’s fairly easy to blend two images in GIMP. All you have to do is: Open the two Images in GIMP. Blend the images using layer opacity/blend mode/layer mask. Export the resultant image as JPEG/PNG.
Layers are an incredibly useful tool in Photoshop (we've actually got a great tutorial on how you can make the most of them should you want to peruse it) and when you dig down into the tools, you'll ...