Finding synonyms for the term "making tough" can help expand the vocabulary and add depth to one's writing. Some options for words or phrases that could be used include "difficultizing," "complicating," "challenging," "frustrating," or "intensifying." Other synonyms could include "hardening," "strengthening," or "fortifying." Depending on the context of the sentence or paragraph, other phrases that might work well include "facing resistance" or "confronting obstacles." Consider varying word choice and using a thesaurus to find additional options to help communicate the intended meaning in a more nuanced and detailed way.