Anointed Procession doubles tokens that effects would create under your control. That includes creature tokens as well as Treasures, Clues, Food, and other token types. White token decks can use it to increase combat pressure, but its broader scope also supports artifact and resource engines that turn tokens into mana or cards.
Avenger of Zendikar creates twice as many Plants with Procession in play, giving later landfall triggers a larger army to grow. Smothering Tithe can create two Treasures for each successful token-producing trigger, improving the mana available for a major follow-up turn. Academy Manufactor adds another layer by replacing the creation of a Clue, Food, or Treasure with a set of all three, which Procession can then double.
Multiple token doublers multiply the result. With both Anointed Procession and Parallel Lives applying to a token-creation event, an effect that would make one token normally makes four. This can produce a large board quickly, but the useful question is what the tokens will do next. Sacrifice outlets, artifact payoffs, and combat finishers help turn increased quantity into a concrete advantage.
Procession does not create tokens by itself or double counters placed on creatures already in play. At four mana, it can also be slower than simply casting another token producer when you are behind on the board. It works best when the deck has enough repeatable or high-volume token production to benefit soon after it resolves, plus a way to spend those resources before opponents clear them away.
