I've had color filters for quite a while now, but only recently I started using them to my advantage. In fact, the orange filter lives -almost- permanently on my lens now.
As you know, I use my digital camera to "preview" the effect the filter will have on the photo. It's not going to be 100% accurate but it gives you an idea.
The only way to know what the filter did to the image is to take two exposures and compare them. This is what I do from time to time to further learn how to use these filters.
This is an example from Monument Valley, in Arizona. Image on the left was taken without the filter, image on the right was taken with an orange filter. They haven't been processed and they were scanned with the same settings.
As you can see, a filter does more things besides adding contrast - things you can't really replicate in post.
The orange filter lets orange-ish tones like red and brown pass almost intact while blocking some of the blue tones, the sky being the best example for this. That's why it looks like the two shots were taken in very different lightning conditions.
Now that we are in snow country, I'm loving the orange filter to make images of the winter. It adds a lot of drama to snowy landscapes - see my latests photos of Indiana and Lake Michigan for examples.
As I said I'm still learning to use them, but I'll keep reporting with more examples in the future.