For some reason you don't lose your cloak when you throw things, so upgrade your strength and cloak.
When it is time to kill something turn on your cloak grab the heaviest object you can lift and chuck it at your target.
They won't be able to find you because you will still be cloaked so you can just keep throwing stuff at them.
This works great on the guys with power armor.
When climbing up a ladder you put away your weapon, but if you hit b to pull it back out you can climb the ladder with your weapon out and usable.
Position yourself a few feet from a low lying object (stairs [recommended], seat of a couch, non-movable bench, or others about the same height) and start running towards it. Just as soon as you start to walk over it, jump. You should jump 2-3x as high as usual.