Offering a mind trick when the challenge (actually boredom to most) of higher reps presents themselves. Taught this when first beginning the heavy breathing squat 20 rep system of training years ago. Helped me quite a bit to get to that final 20th rep. This might be worth something to someone out there. This count system is nothing new.
Other than the regular 1, 2, 3, etc, standard method of counting, we adapt to another way. Starting with the first rep as number one, the following rep will be replaced by the word "and". The rep after that will be counted as number 2, rep after that we use "and" again, number 3, than next is "and", etc.
Example of using this count system: 1-and-2-and-3-and-4-and-5-and-6-and-7-and-8-and-9-and-10-Done.....that's 20 full reps.. The word Done (use any words that you want...F***, S***, eat me, etc) will be used on the last rep of that 20 rep set. The mind /body connection is accepting that the body is only doing 10 reps,according to the mental count, where in reality it's doing 20 reps. Remembering thast the mental aspects of training can be just as much a mental effort as a physical one.
Can use his rep count on any exercise (chest, delts, arms, abs, etc), with high or even shorter, heavier reps of 4, 5, or whatever. The last rep need not be a even number for any set. If this style of counting works for you, than good. If not, than at least you gave it a try. Trying something new in workouts can be it's own reward in BB'ing, at times. Good Luck.