The phrase "going by guess and by God" is commonly used to describe making decisions or taking actions without careful consideration or planning. Synonyms for this phrase include "winging it", "shooting from the hip", "flying blind", and "improvising". Each of these phrases communicates a lack of preparation or thoughtfulness, and is often used to describe situations in which the outcome is uncertain. Whether in business, personal relationships, or other areas of life, relying on guesswork and luck is rarely a recipe for success. It's important to take the time to analyze situations and make informed decisions based on available information, rather than simply relying on chance or intuition.