The packaging

play with the locks

and box making

http://www.rouding.com/shejiyushoucang/pingmianbaozhuang/ganshouzhihemeili-san.htm

http://www.360doc.com/content/10/1014/17/362376_60983943.shtml

http://www.rouding.com/手工专题/纸盒折法.htm

http://www.idoself.com/diy/toys/5715-1.html

good packaging eg