"What I really like is when you've edited an image and you think you're done," says action and adventure photographer Lorenz Holder. "So you take a break to get some fresh air, then come back and look at your computer screen and it's like, 'Oh, that's a bit colourful!' You can immediately tell that it's just too much."

Lorenz is one of the panel of judges for the Redline Challenge, which invites photographers worldwide to push their creative and technical boundaries by exploring the relationship between light and darkness. He will also be mentoring the winner on a personal photography assignment.

With the deadline for entries rapidly approaching, we caught up with Lorenz to get his advice on how best to select your images for the Redline Challenge and get them ready for submission.

So, you've built a large, diverse collection of images that meet the Redline Challenge's 'Light in the Dark' brief. How should you begin to narrow your selection down to no more than 20, the maximum number of entries per person?

Picking the best can be a challenge, but Lorenz says three is the magic number to aim for. "Whether you come back with 20, 50 or 100 shots from one location or session, I would cut them down to three of your favourite images – the real standouts – and no more."

Images entered into the Redline Challenge must be in line with the competition rules and must not be manipulated to fit the Light in the Dark brief if they didn't already. But that shouldn't deter you from bringing out the best in your images using editing software such as Canon's Digital Photo Professional (DPP) or Adobe Lightroom.

When it comes to editing, Lorenz suggests that a little goes a long way. "I often see images where it's obvious that the photographer has pushed the Clarity slider too far, for example. It's a bit like ten years ago, when everyone was using HDR and kept pushing it to the point where everything started to look unnatural. Clarity is a really cool tool, as long as you don't overdo it."

Exposure is another area where it often pays to be more subtle with your adjustments. It may be tempting to try to open up the shadows to expose more detail in a photo taken at night, for example, but this can reveal more noise as well.

"For example, if you photographed a model in a scene that's lit by orange street lamps, but she's being directly illuminated by the blueish light from a shop window, then you would set your white balance to neutralise the blueish main light. But then you can also have fun with the white balance, such as taking it all the way down to the colder side of the colour temperature scale to give you a cool, more industrial feeling."

"If there's a really strong difference in colour between different light sources and the image looks uneven, I sometimes convert the picture to black and white, or simply reduce the saturation a lot, and then apply a warm or cool tone to it," Lorenz adds. "It just helps to clean it up a little bit."

Images should, of course, be pin-sharp where that was your intention. To ensure that a photo looks natural, though, avoid over-sharpening it in software. "I never sharpen images when processing them in Adobe Lightroom," explains Lorenz. "I do it later, because when you're creating a print, for example, you need to sharpen the image differently depending on the size of the print. But the way you apply sharpening is personal taste, really – although I would say that, once again, less is definitely more."

The location where you edit your images and even the time of day can have an impact on the end result. If you don't have a dedicated space for editing, with consistent lighting and neutral-coloured walls, Lorenz's tip is to make multiple versions of your pictures.

"Sometimes I make ten different versions of my favourite image. I may do the first edit in the morning, one after lunch, a third one in the afternoon, a fourth one at night and so on. And then I compare them.

"Out of all these different edits and colour gradings, there's usually one which is exactly how you saw the image, and then you can maybe do some final tweaks to this one. Of course, this technique only really applies when you're working with a couple of images. It's not something that you really want to be doing when you've got 100 pictures to deal with."

It's a good idea to give yourself some breathing space between editing your Redline Challenge images and submitting them. Reviewing the selection with fresh eyes a day or even a week later will help to reaffirm your decisions or let you see where you need to change them.

It can also be helpful to print out your photos at this stage, rather than viewing them on a computer monitor. Holding a physical print will give you a new perspective on an image and make it easier to spot any distracting elements that you may not have noticed on-screen. Try viewing them upside-down and in a mirror as well, for a fresh perspective on their balance and composition.

"Maybe it's also at that point when you could ask a friend to review your images," Lorenz suggests. "But don't tell them the stories behind the shots!

"There was an occasion where I had been standing for six or seven hours in snowfall in Finland," he goes on to explain. "It was absolutely freezing. I came back and told everyone I had a really cool shot, but everyone I showed it to said it was only alright! So I know there is definitely a tendency to rate an image more highly when you've had to fight for it, regardless of how good the picture actually is.

"When we're judging the Redline Challenge, we won't be able to see the energy that the photographer put into taking an image. So I think having a friend who is able to review your images impartially before you submit them will really help."

Lorenz's final piece of advice is to make sure you don't enter two almost identical images. "I had this problem when I was entering a competition. I submitted two similar shots, as I thought they were both cool. But the judges simply said, why should they be making the decision on which is better? The photographer should be doing that.

"This time round, I'm one of the judges, so you should definitely be making the final selection rather than me!"

? Adobe, Lightroom and Photoshop are either registered trademarks or trademarks of Adobe in the United States and/or other countries.