So here goes my Monday reply. On an outside corner lay one molding along one wall and the other along the other wall so that they are overlapping at the corner. Run a pencil line down both sides of the both moldings marking the opposing moulding. Draw the diagonal line on each moulding starting at the inside corner and then cut along the diagonal line.
On an inside corner again run both mouldings into the corner and overlap making sure the inside of the moulding is tight against the corner. If the angle of the wall is less than 90 degrees then you will have to trim the end of the moulding back a little so it will fit tight in the corner. Mark both mouldings where they overlap on the corner. Now draw a line from the inside corner of the moulding to the pencil mark. This should be a diagonal line. Then cut along the diagonal line.
This technique will only work with low mouldings, no more than about 1 inch high. Since you are using quarter round this shouldn't be a problem.
Thanks so much.Sounds like a plan I can follow.Going to try it tomorrow.Got me a contractors protractor and if I find this won't work I will go with planB.