My shower curtain hangs on a curved rod, so the 5 or so inches that was left of the shower liner, I hung on the center of the curve for both panels. That way it is easily hidden.
If you have a straight curtain rod, you may need to pleat the liner by simply putting two of the grommet holes onto one of the shower hooks which will shorten the width.
If you have a fabric covering the liner, I don’t see that as being a problem.
Then I marked a little notch onto my curtain panel where each grommet hole matched up.