The choice of your commander has a significant impact on a deck, dictating the color of cards that can be included within a deck whilst serving as a reliably accessible card that can be accessed each game
Your spells also get into the act
Just need to not get Murktide Regented
Well miracle is an alternate mana cost, so if you draw it as the first card of the turn, you can reveal it and cast it for free, and then use your spell for the turn to recast a keycard that was bounced or drop something from your hand
Again, Doubling Seasons effect will create twice that many tokens, so you will be getting 4 Jace, Cunning Castaway tokens, each entering the battlefield with 6 starting loyalty, same as the original
This is easily the weakest recursion in the list, you have to pay five and you have to have a dork to put it on and you can lose that dork and your bonus value fairly easily to removal or trickery