None of those looks boring to me, they are all excellent photos.
Anyhow, these would be my "enhancements", if they were mine.

Last one of the four.

Excellent improvements from dinasset.

My attempts.
All the pictures I have given a colour boost, plus a slight increase of the red content. My camera, in landscape mode, seems to have an emphasis on the blue/green.
Stream: Colour boost and Curves.
Sun and mist: Adjustment with curves, then added a layer with gaussian blur at low opacity for the distant parts of the image to emphasise the mistiness. Wavelet sharpened.
Empty field: Curves adjustment and Luminosity Mask DD to give some detail to the tree trunk and branches.
Country field: Curves and Luminosity Mask DD to lighten the darkest areas.

david.

Country field.

david.

Another couple of quickly taken, wintry photographs. The Vale of Clwyd, pictured from near Moel Famau.

david.

Thank you so much David. Here my try on one of them.

Mi try on the second photo. Thanks David.

Issabella,
Nice results. You have brought out the detail, but emphasised the "gloominess", and it was very gloomy!

I decided to try to keep the gloom, but have the colours, particularly of the red/brown heather stand out a little more.
I hope it is effective.

david.

I do not come here as often as perhaps I should. However, the 'gloomy' scenes above are quite captivating, so I thought I would add a few photos from a recent trip to the Monaro High Plains that can be played with. As can be seen it was gloomy there too -

OMG, welcome back to this thread! Three very atmospheric photographs for me to make a mess of!
Here are the results.
tree_moss: I've given it a large increase in the green, followed by sharpening using Wavelet decompose to bring out the structure of the moss and tree trunk.
monara_lookout_bush: Overall colour boost followed by a reduction of the green to try to emphasise the tree trunks. Wavelet sharpened.
monara_high_plains: Colour boost plus increase in the red. Luminosity mask LL used to increase the contrast in the stormy sky. Wavelet sharpened.

david.

Thanks David. I see what you say, but I'm unable to get the gloomy at the background while enhance the front.
Here my try with OMG's photo.

Issabella,

A quick approximation of what I did to make the sky more "stormy" (screenshot).

david.

Thank you so much David. That helped me to understand.
I applied masks on these ones.
OMG, very nice photos. Thanks for sharing them.

Issabella and David - thank you for playing with my photos; I enjoyed your interpretations.

This morning a friend sent me a photograph of the first snow on Mount Ainos in Kefalonia, Greece.
I thought that someone may wish to play with it.

david.

My edit of the photograph.
Luminosity Mask MM, Curves on both layers, slight colour boost and removed the cable.

david.

My go: enhancing colours.

In the opposite direction: adding a cloudy atmosphere.

OMG, forgotten to play with your images, excuse me.
Here my tries.



I hope you like them

OMG, I applied my "crystallizing" filter to one of your images.
Far from your fantastic "crystallized" creations, but just an "hommage"