How can I improve my YuGiOh deck?

try to stick to one deck type. in your case i would stick with zombies and keep it almost all zombies. i have a warrior deck and its really hard sticking to 1 type and i try my hardest to stick with warrior no matter how good a card i have but 1 or 2 non zombies is ok and with a 40 card deck i would try to have at most 5 tributes. hope i helped :)