Toning Photographs is an Art, also SHOOT RAW!
A lot of people like their photos with no postprocessing at all, I don't.
I've been told during my years as a photographer a thousand times about how I tone my photographs and such, with a lot of split toning and other ways, like cross processing and render lightnings effects, even the lame old lensflare can be useful somtimes if you know what you are doing just to spread some light.
There's a thousand different ways to tone your photos and I think you should find your own way, there is curves, colors selection, highlights/shadows split toning, crossprocessing, everything that all those instagram filters does, but you can do it so much better.
Sometimes I'm lazy and use Nik Software to tone my photos like vintage etc, if I want a fast result but I almost do 99% of my toning in camera raw, since I don't use LR and never used another photoedit application.
You can always look at other tonings and get inspired and such, try to avoid outblown places, = 100% white if that's not what you are going for.. But it depends on how much postprocessing you like or not, you can always paint something over outblown places and tone them with the photo.
But the most important thing is that you shoot your photos in RAW and have a good program to edit RAW photos in. Because the amount of dynamic range lost in JPGs are horrible.
I also think that there is no overdone photographs.
Since it's just a form of art like anything else, go crazy, play around, find your style. But remember to try to always watch your colors, toning can make or break a photograph imo.
For example, I usually make 2 copies in TIFF 32bitars and edit the subject selective and just mask the subject and the parts of the photo you want to get details from, and then open it in camera raw or LR or any other RAW editor and you can tone them together again if you want. You can do this in a lot of different ways it's just a good tip for close-up to get good details and still keep the bokeh intact. In Camera RAW you can also do selective adjustments, which I guess you can in most applications.. Which is good for small things like light up the face/eyes or also just make the whole backdrop darker.
So point is, play around, never forget about the dynamic range, keep an eye on the histogram and make awesome photos.
I don't know if this was of any interest or made anyone wiser but I hope so otherwise,
if someone have any questions or similiar just ask away or add me as friend. I haven't uploaded so many photos here but I can give good examples if you ask..
art is love.