When we say "patch things up," we usually mean repairing a relationship or resolving a conflict. Synonyms for this phrase could include "make amends," "reconcile," "mend fences," "smooth things over," or "bridge the gap." Each of these phrases implies a degree of effort and forgiveness to mend the relationship or conflict at hand. Other alternatives could include "settle differences," "resolve issues," "put aside grievances," "repair ties," or "bury the hatchet." Regardless of the phrase used, the ultimate goal is to rebuild trust and repair the relationship between two parties.