Ok. I hate "VSCO" answers. Sure, it might be, but VSCO have 999 presets, and it really doesn't help anyone understand what is actually going on.
Fortunately, there are some solutions to this
Load the image into an editor, be it GIMP, Photoshop or whatever else you care to use. Lightroom is not really useful for this, it's not an editor in the pixel sense, which is what you're going to want here.
People, Trees, Skies, Plants, Rocks, Suits, Wedding Dresses etc are all relatively predictably coloured. If you have a shot of a couple standing on some grass with some sky in the shot, odds are they weren't too dissimilar in attire and colour to the sample images show. Furthermore the grass, again, will be similar. Not identical, but similar. (Different times of year, strains of grass, etc will have slightly different hues, and the lighting will affect it too, but in essence, it's Grass Green, and that's our foundation.)
Grab your image, neutralise the whitebalance so it looks good, whack it open in your image editor. Grab one of those similar sample images, open that too. Pick some solid reference colours, I'd go for skin, dress, grass, sky. Select an area of each one and use the "Average" filter to turn it into a solid patch. You could also sample the colour with the sample tool set to a 32x32 sample area or such. This is to avoid the influence of noise in your colour selection.
This procedure needs to be done 3 times really, once in highlight regions, once in shadow regions and once in midtone reasons, in case the other photographer has applied nonlinear corrections.
Once you've got that, use the colour picker / info pallette (Not sure what that's called in GIMP, sorry) and make a note of the RGB, LAB and HSB values for each colour region, both in your shot and the sample. You'll now start to be able to make educated inferences about what, exactly, is going on with the image. Does their grass have a lot more Blue in it than yours? Does it have more blue in the shadows, but oddly, the highlights are a lot less blue? If that's the case, you might be looking at a Yellow/Blue crosstone effect, for example. (Looking at your colours in HSB/LAB removes this light/dark confusion, and I find they're much easier to read than RGB).
Once you've isolated what's happening, you can start to make moves on your own image to push it in the direction of the image you like. The overwhelming majority of the time "What have they done to achieve this look?" is colour based, and can be analysed and reproduced without any real wizardry. Obviously some retouching techniques will exploit filters and tools that if done well, will be seamless, but if it's just a colour look you're after, you can get there most of the time with analysis.
Of course, you can just install VSCO/LXC/Nik/Mastin Labs and mash buttons until you get a look you like
DSC_5401
