When it comes to expressing the act of making mistakes, there are several synonyms that can be used instead of the phrase "screw something up". One alternative phrase that can be employed is "mess up". This term conveys the notion of committing errors or blunders in a less explicit and colloquial way. Another suitable synonym is "botch", which signifies a failure or a mishandling of a task or situation. Additionally, "fumble" can be utilized to describe the act of making errors or mishandling something, often resulting in a negative outcome. "Muddle", meaning to confuse or misplay, is another appropriate term when discussing mistakes made. Ultimately, using these synonyms allows for a more varied and refined language when expressing the concept of making mistakes.