Black Gate/Mt. Doom
It is a good idea to have Stealth Of The Shire 1 and Courage Of Sam 3 to get past the enemies. If you use it, you will block all attacks on Frodo and Sam. Note: This is the last level of the game it does not work in multi-player mode.
Gaining experience
It is always a good idea to complete the extra battles that become available to you throughout the game. By doing this, all of your heroes will be at a higher level when it is time to use them in the difficult later battles.