My advice: Actually go and learn some martial arts.
People praise my fight scenes a lot. I'm a green belt in karate, did it for about eight years, and I've also spent time learning bits of Judo and Iaido (the latter I studied in Japan when I was an exchange student there).
I take creative license to make my fights more fun and easy to read, but when I draw a fight, it's based on actual experience of what it feels like to punch, kick, swing a sword; how the body follows through with momentum, how heavy a sword is and the kind of arcs things move in. I don't have to look at a photo and try to guess which muscles are tensed or where my character's centre of gravity should be; I know it because I learned how to punch. Even just a basic class would teach you about the stances, where the weight should be distributed on your feet, how the torso is used when punching etc. It really helps, and also you learn how to defend yourself and it's good for core strength and fitness, so win-win!