Apropos of this Covercritics post.
The current cover is very solid in all its basic decisions, it just needs a few key adjustments to bring it up to a professional standard that will do the job of persuading browsers to become potential readers.
I'll break these current issues down into three parts - front cover and artwork, back cover, and fonts.
Front cover and artwork
Here is the cover as it stands:
Nathan on Covercritics already pointed out that a key fix is making the figure bigger, and I'll be resizing that part.
There's another issue which is making this cover hard to make out and sapping its intensity, and it's that the artwork is dark and muddy.
It's easy to let this happen in digital art where the subject is meant to be literally and/or atmospherically dark, but for the dark to be effective you need the sharp contrast of highlights too.
So I've worked on the contrast, brightness and saturation:
Specifically I have:
Increased the brightness/saturation/contrast overall.
Brought up the colour intensity of key background details. It makes the cover more visually interesting, and it's also storytelling: the Communist flag and the 'Don't Tread on Me' stencil get across the idea of a civil war at a glance.
Worked on the figure. This is the most important part of all. The current cover has this figure very dark and it's true that the figure should contain the most intense values, but that should also mean the brightest highlights. I especially worked on the face, as the most central and important part of the cover. I also highlighted some other areas of the figure and brought in a little more variety of colour - e.g. more red in the scarf, more yellow in the bag and its strap. Another common tendency with digital art is for it to slide into monochrome and end up looking like a sepia-tinted olde timey photo. Even in a light like the polluted yellow dusk at play here, there will be variations of colour, and it is these which can help make important aspects of the art draw your attention.
Before I move onto the back cover, the other thing I've changed here is the title colour. Again, having contrasting colour and tonal values brings energy into a cover.
Back cover
The issue with the back cover is the semi-transparent boxes under the copy. I can appreciate their purpose: while it's great to have this full-jacket artwork, if you place text directly over it, it becomes illegible.
But the current solution of boxes won't work, they let down the professional look.
I'm going to demonstrate what my solution would be, but as I don't have the cover in question as a layered file to play with, I'll have to grab some other artwork of a similar nature to use.
So first off, here's the problem with placing the text directly over busy background art:
It's uncomfortable, if not impossible, to really read.
And here's my solution:
This is a layer between text and art which I have filled with a dark-to-white gradient, going from dark on the left, white on the right. Then I have changed that layer's transparency setting from 'normal' to 'multiply'. Very simple.
(I say 'dark' rather than 'black' because I find it works better to use a dark brown or red for the dark part than black. Black can deaden the colours underneath.)
The other issue worth addressing is that the back-cover copy is a bit of a wall of text right now.
I often advise authors to cut down on blurb length a little - authors can tend to put in a little too much, being so close to the book. But actually I'd say this blurb is already an appropriate length. I might advise revisiting the author bio. The only thing that earns its keep on a back cover is that which helps persuade the browser to become a reader. So the awards stuff is great but the stuff which is more personal colour could be saved for the longer author bio inside the book.
Cutting down in volume of text where you can will give you a little more room to address the styling of text, and how you can use that to break up your information into clear and inviting units.
There are four distinct units of text here - the longline at the top, the blurb, the reader praise bit, and the author bio. Currently everything (except the longline at the top) is of a very similar weight and styling, making it feel like on long and dull block.
Instead these should all feel distinct from one another, and weighted according to importance.
The tools you cause to divide up blocks of text are: clear separation between units, font style, font size, font style (bold/italic/etc), text colour and text alignment.
So here's mine:
Now when a browser clicks to see the back page, their eye is going to drawn to a couple of places first - the phrase "chilling, brutal and completely unique" and the longline at the top.
If you can reduce length in the author bio I have in my demo, it just gives you more that precious bit more back cover room to play with.
Fonts
I have changed the blurb font to a serif, another change Nathan already pointed out as important. As he said, serif fonts are more suitable for any long-ish block of text. There's a reason novels are always printed in serif fonts! It's a lot easier to read.
But I also want to bring up fonts more generally.
The existing title treatment is great, and I think the by-line works too.
But the rest of the fonts need revisiting. Everything else is currently in something very like Arial and it just brings down the standard of the cover. Arial is a font we associate with word processing, emails, website.
The place that it's really conspicuous is the tagline on the cover, "A post-apocalyptic action survival thriller".
There's a few issues with that tagline. It doesn't fit the physical space very well, and moreover there's a lack of confidence being communicated her both in the wording and the font choice.
The tagline makes the book sound generic. I mean it literally just describes the genre. Personally I'd use something more like that last line of the blurb, which is much more effective: "When civilisation falls apart, just how hard will a man have to fight?"
Except you want to be as punchy as possible on a cover (and have something shorter that neatly fits that above-title space) so maybe just "how hard will a man fight?". After all, the imagery is already telling the 'post-apocalyptic survival' part of the story.
It's a good instinct to introduce a second font apart from the one used on title and by-line here but as I say, not the current one. You don't want to go OTT of course, but something more distinct and less familiar from mundane life!