I was in the same boat with you a couple of weeks ago as my approach was trying to use "tricks" such as counting lines, etc. I could only get at most half of them correct, not to mention spending a lot of time on this subsection.
Then I said screw it, I'm going to try to actually visualize the image in 3-D first and use tricks as a last resort if I need to decide between two possible answer choices.
Soon enough, this became one of my competent subsections as I can get 13-15 correct each time now.
So try to actually visualize the object first before looking at the answer choices. You'll slowly but surely start to get the hang of it and will eventually be able to eliminate wrong choices and be able to answer it pretty easily.
Trust me, it'll work. You just need to train your eyes and brain to visualize a 2-D image into a 3-D image.