That's a very good question. I'm sure the responses will be as varied as the users. I say that because with DRO you get so much flexibility that you are only limited by your imagination.
I'll start by giving one example that works (for me) in both ID and OD work. When I start cutting a diameter, I skim until I get a cleanup, if I'm close to finish size anyway, and zero the readout there. I back away, stop the machine and get a good, accurate measurement of the diameter. On my Sony, and I expect the majority of units, I can manually enter a value. So safely away in -Z-, I dial the tool back to the position I cut in.....and where I set the zero, then enter the actual cut/measured diameter value. Back to the work, another pass where I verify that it cut to what I dialed. I do it again as I approach the finish diameter. On the last couple of passes are important that the depth of cut be the same, so any pushoff is predictable. If it consistently cuts 0.0010 less than I dial, then I could look for the problem, such as tool height, or I could just dial in the extra 0.0010, and on the last pass, it should be right on target.
Another tip is while deep in a bore, where you cannot see the back-side of the hole or the bar, one way to make sure you don't back away from the cut too far and mar the bore is to just get off the cut diameter, and pull the tool back out. And if you're facing the bottom of the bore, if you have set the bar as I described above, you don't have to guess when you face back to the center. You know when you it 0.0000 diameter. Going past will possibly chip your tool because then it would be running backwards on the facing cut.
OK, there's mine to start. I'll let others add their tips. As I said, there are many, many things you can do with them.