Yes, TFE was definitely the hardest section for me too! If you are aiming for a 20-21, I would suggest skipping the TFE section and go straight to the sections you are good at and acing those first! And then if you have time, do the TFE.
I sort of got the hang of TFE by using CRACK DAT's videos explanations. I also got a sheet of paper and drew out what I expected the missing view would look like by visualizing it. It sort of helped. You can always try line counting but it may not work for all the problems.
I was decent at pattern folding. Try origami, seriously! I usually just focused on one part of the object.
Good luck. But PAT is really not really that important. Aim for a 20+ and you should be good!