This is where I was. The grass was much too high, so I cut it back.
The wrinkles will get a treatment below.
With a needle I pull the fabric up where I want excess fabric/wrinkle.
The wrinkles are sewed down in the folds with a little straight stitch.
French knots in different sizes fasten the wrinkles and hide the sewing stitches.
I also added a little rock (about 7 mm). This rock is glued on a threaded piece of plastic.