What are appropriate objects of 制作?
After going through a few online examples, I think this is what 制作 actually means:

To make something physically that requires a level of skill or artistry, such as, a movie, a cake, a greeting card or a toy. Example:


  韩国制作巨型巧克力高跟鞋迎接情人节 (South Korea has made a gigantic pair of chocolate stilettos to welcome Valentine's Day)


Since 制造 is also mentioned, to provide disambiguation, 制造 means to manufacture or mass-produce something (both physical and non-physical). Example:


  这AK-47是前苏联制造的 (This AK-47 was made in the former USSR)
  制造垃圾 (churning out rubbish)
  制造欢乐气氛 (creating a joyous atmosphere)


To build or construct something, usually big, we can use the word 建造. For example:


  建造楼房 (construct a building)
  建造卫星导航系统 (build a satellite navigation system)