Several areas of the game require you to open a door and enter into an area, at which point you'll be attacked by enemies. In some of these places, if you're health and/or force energies are low and need to be given time to recharge, simply stand back past the doorway to the previous room. Most of the time, the enemies cannot pass the room they are in, and will stand huddled in the doorway. Also, using Saber Throws (Or, later in the game, when Anakin aquires Force Lightning) you'll actually be able to get to these safe spots and kill the enemies that are standing just outside the doorway. This is especially helpful during missions like the "Assassination on Mustafar", where you'll constantly find yourself fighting Brutes, Guards, and Battle Droids.