The economic challenges and production processes of Sustainable Aviation Fuel (SAF) have significantly slowed its commercial adoption. This review examines the current feedstocks and conversion methods for cost-effective SAF production. The focus is on alternative feedstocks such as lignocellulosic biomass, waste materials, oil-seed crops, and microalgal oils, which could replace traditional crops. Conversion methods like the Fischer-Tropsch process, hydroprocessed esters and fatty acids (HEFA), and non-thermal plasma are cost-effective and show high potential for SAF production. However, technical issues, including immaturity and high costs, require further optimization of these processes using alternative feedstocks. The review also highlights critical factors affecting reaction efficiency, such as feedstock properties, reaction conditions, catalyst reusability, and supporting materials. Ultimately, the paper discusses the challenges, solutions, and opportunities for cost-effective SAF production.