Those manuevers do have some opportunities for downgrades. Here are the typical gotcha's

Tophat
radius of each 1/4 loop need to be equal. I tend to make the radii at the top much smaller than the bottom because I am out of airspeed.
1/2 rolls need to be centered in the vertical lines (up and down).
as mentioned, manuever centered and symetry

Double I
radius of each 1/2 loop need to be equal
the roll needs to be immediately at the point where the 1/2 loop is complete. Any straight line after the half loop is completed but before the roll is obvious and a deduction
the top and bottom horizontal lines need to be the same length as the diameter of the half loops