"Wastest" is not a proper English word. It is likely a variant or typo of "waste" or "wasteful." The antonyms for waste are "conserve," "save," and "utilize." The antonyms for wasteful are "economical," "prudent," and "frugal." Using these antonyms can help individuals be more mindful of their consumption or spending habits, and perhaps even contribute towards a sustainable lifestyle. It is essential to note that being frugal or economical does not necessarily mean living a restricted, limited life; rather, it means making conscious choices and being mindful of the environment and resources around us.