On all my trackage I use Midwest Cork O-gauge roadbed. On the outside rail of all curve trackage + 10 inches in and out straight trackage, I use 1/2 of a N gauge cork roadbed ( gives about 1/8 inch rise). Looks good and is not overkill. Works on 0-54-thru 0-72 diameter curves. No calculating and gives a prototypical 'elevated curve' look. I only use K-line Super Snap track and successor pieces.
Walter