David, good results on both pictures.
Dinasset, I like yours a lot too. A question, what is a bilinear mask?
I wanted to get colour on my tries. But perhaps I added over colour on them.
I levelled both photos, too.

Still not quite correct, if you use guides to check. By the way, if the lens axis isn't horizontal, perspective will make vertical lineson the sides lean inward (camera tilted upwards) or outward (camera tilted downwards) to you you check vertical lines around the center of the picture.

Issabella,
bilinear mask, just my shortcut to say:
- added a layer mask
- applied on the layer mask a B&W gradient using bilinear gradient shape
In one case it allowed NOT to APPLY the multiply mode to the central horizontal stripe
In the other case it allowed to APPLY ONLY the screen mode to the central horizontal stripe

This time I opt for something completely different:

Thank you Sallyanne for your contribution . Nice result.
Thank you Dinasset for your explanation about bilinear mask. I have to test it, too.
iarga, you did such a novelty effect. I'd like if you tell your flow to get such a nice effect. Thank you so much, too.

Issabella, the most importand filters I used, G'MIC "Tone enhance" and "Curves". Thereafter little things as smoothing. But I'm not satisfied with the tree tops (after extreme tone mapping). Maybe someone knows a quick way to deal with that. I supose I have to learn more about masks. But thats not always quick and easy.

Here my next one, also with "Tone enhance" and "Color grading":

For the lake I used a mask on DDD
G'MIC Basic Adjustments lowered brightness on masked layer, added contrast and gamma, hue and satuaration.
Sharpened with Inverse Diffusion.
The picture with the nice building I used layer mask MMM
adjust gamma and unsharp mask.

iarga, your last result has a very nice luminosity. I agree with you about masks but I'm following David's tutorial and little by little I feel myself a bit more confident.
Serious Tom, I like your results, too. Thanks for sharing your flow on them.

I found this photo taken in 2012. A challenge.

Iarga,

The secret to learning to use masks is to play. I frequently find that I get totally the wrong result, so just delete the layer or the mask, have a re-think and start again.
Of course, you never see my total disasters!!! Keep playing and have fun (and occasionally a bit of frustration, it has to be admitted).

david.

Issabella,

Sorry. With your last challenge I have cheated!
I felt that the photograph had two focuses (focii?) and was pulling two ways. So I have made two photographs from it.

The right side felt like a path leading to (?) somewhere. I enhanced the colours, added a layer mask with a radial gradient to try to lead the eye along the path. Sharpened.

The left side of the original picture made me think of winter colours. The sky and the lake were over-exposed, so little I could do with them, but I accentuated the colours of the trees and fallen leaves - DDD Mask to bring out detail in the darkest areas. Colours perhaps too much?

david.

Perhaps there is a third photograph in there!
Similar process to Winter Colours.

david.

interesting interpretation, David !
I kept a single image, which you may call "where should I go?"
-dup
-retinex low, multiply
-new from visible, doubled contrast on A and B (g'mic mixer lab)
-curve to lighten
-downscaled

Thank you David. Well done. we are free to change or split our photos as we want them. I like the results you got. Yes, it was taken in December so colours reflect that cold atmosphere.
Dinasset, I like your result getting more deep view at the horizon. So many enhance tools you are a master on. Thanks.
My try

Another two more photos.

perspective transform
unsharp mask

For the picture of your lovely dog I have done very little.
DD luminosity mask to lighten the face a little and wavelet sharpened.

The picture of Port Meirion (very close to home for me!), multiple layers with D, DD, and DDD masks. Slight adjustment on each one to try to find some detail in the dark areas.
Weak winter sun and very little in the way of white clouds produces very high contrast. Boosted colour and wavelet sharpened.

david.

Dinasset, I like your results on both pictures.
David, I'm happy you recognized Port_Meirion. Part of my family lives near too. I like your results too.
I applied on it a Bi-linear gradient vertical on left side (the darkest zone) I learnt this from Dinasset.
On Lucca picture I applied Luminosity Mask DDD. I learnt this from David.