p.1 #1 · Swiss Alps landscapes, not sure if oversaturated
Here are two pics from a recent trip to the Swiss Alps. I lowered the exposure slightly so that the sky wouldn't be too blown out. To compensate, I lifted the shadows and blacks slightly and increased the contrast and saturation.
I've asked a few non-photography friends to take a look at them and they said originally the photos were slightly unsaturated/had dull colors. I'm inclined to agree with them, hence the contrast/saturation boost. Basically, my eye is horrible with these things and I just want to know if these two photos are oversaturated or not (or if there are any other issues with the photos you guys have).
p.1 #2 · Swiss Alps landscapes, not sure if oversaturated
When shooting in the mountains, the UV light may be a problem. A UV filter can help. UV light tends to add a haze effect. (A "haze" filter may also alternatively help.) Also, the blue from the large expanse of open shy adds some blue to everything. Both effects lower perceived contrast and saturation and require PP corrections, although the better the originals are filtered in the field, the easier any residual PP corrections later.
As to the amount of saturation to add, it depends upon your audience. Non-photographers generally prefer more saturation. Photographers are more likely to complain something is too saturated.
p.1 #4 · Swiss Alps landscapes, not sure if oversaturated
One thing you can do in PP is to make different selections of foreground and background and apply different corrections to each. The haze and blue cast is generally more obvious in the background than the foreground. That's why one-size-fits-all contrast and color correction isn't ideal. You can apply less correction to the foreground and more to the background. However, if you apply too much to the background, it can look unnatural, so careful judgement is in order.