Walls and Ceilings - Rounded corner trim

I am putting in some trim in a house that has standard rounded drywall corners. The trim is cheap, standard wooden baseboard, approx. 7/16 thick by 3 1/2" high available at any Home Depot.
Of course, the trick is to get the trim to look decent around the corner, or not, if that is an option. I have plenty of tools, just not the experience. I have surveyed some new homes that use a much thicker and more expensive trim, which I do not have the priviledge to use, but which make it easier to wrap.
Thank you for any explicit help. Pictures would be nice or drawings, etc.
jomamameister

Do you know (or can you figure out) the radius of the rounded corners? Do you have access to a router or shaper with a bull nose bit with the same radius?

You could run some stock through the router or shaper cutting a quarter circle with the bull nose bit. Then rip the stock to make a filler piece to fit between the rounded corner and your flat baseboard. Run enough stock to make several fillers then cut them to the desired length (3-1/2") Use a spot of glue to attach them to the corners, then install your base.

Hope you can follow this - it's actually much easier than it sounds. :)

You could take a square piece of clear lumber twice the width of your corner radius plus 1 inch (say your radius is 1/2" that gives you a 2"x2" board) cut it into 3 1/2" pieces.

Drill the center out with a bit the same diameter (2x the radius) as your corner (in the above example a 1" bit). I'm guessing this would take a drill press and some kind of a jig to hold the piece upright while you drill it.

now cut it in half twice splitting the flat edges.

Now you've got four corner blocks with a perfect fit. You just but your trim up to the blocks on each side of the corner.

Of course I've just described the hard way to do what jomamameister said to do with the router. With the router you could also run some kind of bead on the edges to dress it up.

But corner blocks is what you want.

Run the side pieces to the edge of the radius with a miter of 22 1/2. then cut a piece to fit in the middle. Caulk.