Conserving ammo:
When facing enemies on Skull Island, you should always try to conserve ammo. Find bones, sticks, and spears, but do not throw them. Just get up close and press Fire.
Fire spears and bones:
To make spears and bones inflict more damage, light them on fire.
Venatosauruses:
To easily kill Ventatosauruses, if there are bushes where it is standing, use a fire spear or bone to burn it.