There was a time, back in the early days, when generals cost the same for subsequent castings
But for those looking for condensed advice: the ingredients of truly fierce competitive decks are infinite combo pieces, tutors to find them quickly, resource acceleration (mana rocks) to cast all those cards faster, and cheap interaction to stop opposing combos developing
Finality counters work on any permanent, not only creatures
Non-serialized Ring cards are mechanically identical to their Serialized versions
Gameplan The general gameplan is to eat the cards in your opponents' hand and run them down on resources so that Davriel, Rogue Shadowmage can close out
We also have scry payoffs outside of our commander: Arwen Undomiel and Elrond, Master of Healing pump our team, The Temporal Anchor lets us play the cards we bottom, and Lost Isle Calling can take an extra turn while drawing cards