Here's something for the collectors...
Buy advance sale tickets from Animate for the upcoming Evangelion 2.0 movie and you can get your hands on one of these countdown sticker calendars. It comes with a set of 22 stickers for a small extra of 638 Yen (US$7). Only available for purchase from April 18th onwards.
In other words, get the calendar now then wait 22 days before June 27th before you start sticking. Or you could just go for one of the clear folders now... Wouldn't mind a wall scroll showing the whole gang are together.