In Dragon Roost Cavern the miniboss keeping Medli hostage consists of two green bokoblins and a moblin.
After the short cutscene plays showing you that Medli is being held hostage, roll forward twice and attempt to do five regular B attacks (sideways slashes), each time hitting both bokoblins and adjusting position if necessary. After each bokoblin has taken five hits of damage, perform a quickspin and that will finish them off as they each have seven health. If at any point the bokoblins begin to shield your attacks, wait for them to try and swing their sword before you attack again to continue the combo.
After the moblin gets dropped in, target the moblin and perform three stabs. Ideally the first stab will hit the moblin twice, this getting four damage out of three stabs. After getting in these three hits. Back up for about around one second and then perform a jumpslash quickspin to deal six damage and eliminate the moblin who has ten health.
Once you have the Master Sword, all bokoblins and moblins can be defeated with a single jumpslash quickspin.