Accept the diversity of students' aptitude and sense of values
There is a very wide diversity of students' nature.
There is not "the best way of instruction".
Some way of instruction fits to a student, but it does not necessarily fit to other students.
It is not bad that some percentage of students in the whole do not like mathematics.
There is a very wide variety of disposition/aptitude. Each should be respected.
Distinguish the following two :
Instruction for raising the standard of general public
Instruction for developing what ability each student has indivisually
and be sure which you will do.
Teaching methods are different between these two.
As to the instruction, simple is the best.
Teach what should be taught, and do not teach what should not be taught.
In particular, tell the truth, and do not tell lies.
Understand each subject clearly yourself.
There is a variety of "truth" (levels of "truth").
"Truth" for students of primary 1, "truth" for students in a highschool, "truth" for engineers in a field, "truth" for mathematicians, etc.