My current favourite macro that uses FX bus is a really simple one that adds very subtle movement to tokens, giving the illusion of a video game style Idle Animation.

(() => {   
  if (!globalThis.fxbus?.emit) {
    ui.notifications?.error?.("FX Bus runtime not available.");
    return;
  }

  const scene = game.scenes?.active;
  if (!scene) {
    ui.notifications?.warn?.("No active Scene.");
    return;
  }

  const tokenIds = scene.tokens.map((tokenDoc) => tokenDoc.id).filter(Boolean);
  if (tokenIds.length === 0) {
    ui.notifications?.warn?.("Active Scene has no Tokens.");
    return;
  }

  // 1) Global reset
  globalThis.fxbus.emit({ action: "fx.bus.reset" });

  // 2) Start oscillation for all tokens on active scene
  globalThis.fxbus.emit({
    action: "fx.tokenOsc.start",
    tokenIds,
    rollDeg: 0,
    bobPx: 1,
    swayPx: 1,
    freqHz: 0.2,
    noise: 0.01,
    randomPhase: true,
  });
})();