--In Math, avoid using examples that could result in the correct answer even with incorrect steps. For example, avoid questions that involve the number 2 because 2+2, 2*2, 2^2 all have the same result. It is difficult to know whether the learner actually used the expected technique.

--After a problem is solved, reflect on the given data. Ask questions like "How would the answer change if the given value was x = 40 instead of x = 4 ?" or "What if the value of x was not given at all?" This really helps in understanding the concept required to solve certain problems.

--Choose easy-to-recognize variable names. For example, use a, b, c instead of alpha, beta, gamma. Avoid confusing variable names. For example, avoid using "n" and "m" in the same problem (they sound and look similar)

--Non examples are as important as examples.

--Ask learners to give examples with certain criterias. For example, while discussing bijective functions, ask one learner to come up with a function that is injective but not surjective, another learner - surjective but not injective, another learner - both, injective and surjective, and another learner - neither injective nor surjective. And then have learners compare and contrast their examples.

--While discussing an "If ... then ..." theorem, explore questions like "Does the converse hold?", "Does the inverse hold?", "Does the contra-positive hold?" (Spoiler alert: The contra-positive always holds)