If you shoot a moss arrow at the ground it creates moss so you don't
make a noise while crossing the pad. If the moss doesn't reach the
whole way across you can shoot a water arrow at it and it'll become
longer.

If you drop an oil jar in front of a doorway or a narrow path so it
covers the whole way, then lure an enemy towards you so when he's
rushing you can set the oil on fire with a fire arrow. When that
happens the enemy is killed almost instantly.

If you need to take out a guard but cant get behind him, and don't
want to take him out in regular combat you can just hide in the
shadows and shoot him in the head with a broad head arrow.

If you've fought undead (like in the Abysmal Gale) you'll know it
takes at least five arrows in the chest before they die (and sometimes
it doesn't even kill them) or it'll take however many knife hits,
there is an easy way to kill them. (besides holy water) You can throw
a flash bang and that will not only blind them but take away half
their life. Another flash will finish the job or you can engage in
combat, which is now far easier for the zombie has been reduced to a
regular human's life or less.