There are several synonyms for the phrase "conjure up." One alternative is "summon," which implies a sense of command or authority. Another option is "evoke," which suggests a more mysterious or subconscious process. "Create" is another synonym, and it suggests a proactive and intentional act of imagination or visualization. "Invoke" is similar to "conjure up" in that it implies a magical or spiritual aspect, while "imagine" is a simpler and more straightforward synonym. "Bring forth" is another option, and it suggests a sense of effort or labor in the process of conjuring up. Lastly, "manifest" suggests a sense of tangible or visible results from the act of conjuring up.