Among other things, prepare by;
* having plenty good food and potions
* always start in the morning to avoid night spawns at the end
* have full rested bonus for stamina and health regen
* i haven't tried this, but maybe to make a lot of noise (using pickaxe on metal or stone should work), to call and clear out mobs from the nearby areas. Before summoning Moder.
* if you're in real trouble - run away, reload, and keep going