Repeat nouns rather than using synonyms or pronouns: The first (red) of the following pairs of sentences is more readily comprehensible than the second:

The killer whale tosses the penguin into the air and generally torments the penguin before it eats it.

The killer whale tosses the penguin into the air and generally torments its prey before it eats it.

Alex has 4 friends. He wants to buy each friend 6 cookies. How many cookies does he need to buy in all?

Alex has 4 friends. He wants to buy each of them 6 cookies. How many does he need to buy in all?