When I was searching for tutorials on this skill, I've seen many tutorials on how to blend images and each of them showed a different way of doing it; at the time I picked the one that was the easiest one to me (it was a long time and the site I learned it from is closed), and that's what I'm gonna show you in this tutorial.
I'm gonna use two images for the tut, but you can use as many as you want in yours.
I don't use PaintShopPro so I don't know if this works on it, too; first of all, open both images in Photoshop - I chose two (guess who, guess who? Yep, that's right xD) Thorin Oakenshield ones - as shown in the image below.
I'm making an header blend, so I cropped both images to the same height - to see how to blend two different-sized images, check my other blending tutorial.
Create a new file - in my case, it will have the same height as the original images - and fill it with any color you want; then, move one of two images on the new file as shown below.
Select a rectangle area as shown above, then right-click on the selection and click feather as in the image below.
When the feather tab option opens, you set it to 65 - I find that is the best level for this kind of work, but you can set it to 60 or 70; it just has to be a similar number.
Once you selected your feather radius, click your keyboard's Cancel key (the one above the Enter key) to delete the image side until you're satisfied with the level - see image below for reference.
Now take the second image, and move it above the first image in the new file - you might have to make some changes, i.e. I had to rotate the image horizontally - and use the feather option again, the same way you did with the first image, until you have a result similar to the image below.
After that, from the main top menu select Layer and then Merge Visible to finalize the blending.
The blending is done; you have a brand new header on where to add brushes, text, textures, use actions or filters to spice it up. Enjoy your new image! ^.^