Some miscellaneous things that might be helpful:
-You can use outfits that give more memory appeals to give you an edge in the money/fan making minigames, since they give you an extra die. This works even if the leader isn't the correct rank for the outfit. Just remember to change it when you do a Live. On that note, accessories that give fan/money/exp bonuses also apply to the minigames.
-You can hold the d-pad while pressing notes that do not require the d-pad input. This is good for songs that like to have alternating d-pad notes or a bunch of them together with non d-pad input notes.
-You can sorta cheese the makeup minigame by pressing the home button to suspend the game temporarily. Take a picture of the makeup icons before they flip over, and have it on the side when you resume the game.