"Mental rotation is trivial for me.
I just "know" it, even though I can't see anything but black in my mind's eye.
For example, on the IQ tests which ask you to determine which rotated figure matches the example, I don't even have to look at all the possible solutions. I just know which one is correct, in a fraction of a second. It's not just guessing, because my scores were very high. Also, with jigsaw puzzle pieces, I often just know where a piece goes; not only that, but my fingers can rotate the piece to fit the hole without any conscience thought. I just pick up the piece, and it just fits into place.
I'm also good at "cube net" problems and can easily lay out a flat arrangement of polygons which will fold up into the desired shape.
I'm not particularly good at estimating distances, but I can accurately find the center point of distances from inches up to 10 feet or so. I'm fairly good at estimating angles.
For a recent programing project, I had to create line segments to form characters (letters, numbers, and symbols). I had to trace out the first few on paper, but I was able to do the rest without any sketches. Also, due to my desire to minimize the numeric notation, I directly entered the coordinate values in base-36 arithmetic. Here's an example:
case 'A': pts = "0A,6S,CA;3H,9H"; break;
case 'B': pts = "0A,0S,8S,CP,CM,8J,CG,CD,9A,0A;0J,9J"; break;
case 'C': pts = "CD,9A,3A,0D,0P,3S,9S,CP"; break;
How can I do that so easily? I have no idea."