The easiest way is to either craft or find some Garnet Amulets (the ones with red stones as cores) those each give +1 and you can equip 4 of them. Or you can craft or find Ruby Amulets, they give +2 and you can also equip 4 of them. Ruby ones are much harder to get as the materials for them are found in Werewolf Caves.
Also, you should try to get the actual fighting skills as well, they do significantly more damage than normal attacks.