You do not need expensive software to create book covers.
Since I published my ebook through LeanPub, I already had a front cover for my book.
Of course, when I create the print book I need a full cover including spine and back blurb.
I have used ‘Serif PagePlus X4’ for all my covers. A pretty old version of Serif PagePlus, but it has everything I need to create covers
Serif used to provide free versions of their software. They also tend to sell older versions of their software pretty cheaply once a new version is released e.g. at the moment Serif Pageplus X9 is on offer for £19.99
Serif have a new product called Affinity Publisher which is currently in free beta and cross platform.
I like Serif because it is easy to understand and easy to use and resize and exports well to different formats.
Creating a cover can be hard but both CreateSpace and Lulu have templates and online editors.
I tend to use the ‘single image’ version of the page editor - so the only thing that is really hard is the spine.
With CreateSpace I used their editor and lined up the text on my spine with the ‘show book title’ option that they provide in their wizard.
With Lulu, once you have uploaded the image, they chop it into three sections: back plate, spine and front cover, so you can easily see if you have the blurb in the right place.
I started with CreateSpace wizard, but realise that I should have used the Lulu one first since it is easier to see if you have made the spine and overlay in the correct place.
Once CreateSpace have approved the image, the online proof review is a great way to see if you have lined up your cover properly.
I exported to tif for CreateSpace for the final cover, but my initial exports were all .jpg because they were smaller to upload.
For Lulu I exported to .png.
Lulu provide a pdf for the barcode that you have to add to your cover. Fortunately Serif PagePlus X4 (and beyond) will open PDF files, so I was able to copy and past the bar code on to my cover very easily.
For CreateSpace I just left the area blank where they add the barcode automatically.