The render settings were based on LWF (Fig.19a - b). You can read a detailed description here:
and here: https://www.chaosgroup.com/forums/vbulletin/showthread.php?t=33917
Working with LWF often results in a final picture with low contrast and weakly saturated colours, which is why the main goal of post-production is to strengthen these aspects. I have no general algorithm of actions; for each image I have a specific sequence. Below is just one of the variants, but if I work with LWF I always begin in the same way: I save the results of the render in 32-bit format (.hdr or .exr) to work with it like with an HDRI (to apply Tonemapping in Photomatix or in Photoshop, for instance). All of the whys are covered in the LWF detailed description at the link above, and it's quite obvious really. 32-bit formats, unlike 16- or 8-bit ones, contain enough information about an image for the reproduction of linear colour space, thus providing detailed correction of an image's colour and brightness. So there is some sense in making all the corrections before converting the image; stay in 32-bit mode as long as possible, and go into 8-bit at the end of work, or when there is a necessity to use software which doesn't work with 32-bit formats (most plug-ins for Photoshop or After FX).
In my case, I made some adjustments to the gamma, brightness and contrast with the Exposure tool, with subsequent colour corrections made using the curves. If it had been necessary to work with layers or use a lens flare in After FX, for example, then I would have converted the image to 8-bit (Fig.20a).
The post-production of night renders was different to the day ones, mostly with my active use of the lens flare to make the headlight reflections and glares on the hull more realistic (Fig.20b).
And that's all! I hope you have found this helpful. Cheers!