We need more edges so cut in the green edges shown.
Now reshape the cushion to look something like the picture. Add more edges if you feel the need.
From the top, make the cuts shown.
Now adjust edges and verts to give the top of the cushion a nice bulge. Now select the edges shown in green all around the cushion and chamfer them by 0.8 or so like we did on the other cushion. Make sure you do not deselect the edges. Go into poly mode select the thin row of edges between the chamfered edges and extrude them out then go back to edge mode and chamfer the selected edges by 0.05 just like we did for the other cushion.