Don't think of it as a cigarette. Think of it as the thing that has been missing from your hand. ---《老友记》第一季 第三集
别把它当成是支烟，把它当成是你想念多时的东西。
think up，think out，think over，think of.
think up，think out侧重于思考的结果，即是否想出了办法、计划等；
think up主要表示“设想、构思”之意；think out主要表示“仔细思考并研究出（计划等），或者想透问题”等，
两个短语均为动副结构；
think over也为动副结构，侧重于思考，不涉及结果，表达“深思熟虑，仔细思考”之意；
think of主要表示“考虑，关心，想起，对……有某种看法”之意，为动介（动词十介词）结构。表示看法、评价之时，常用一些副词来修饰，如think much／a lot／a great deal／highly／well／ill of…（对……评价高／好／不好）；
若问评价如何，觉得怎样，常用what…think of…；
若表示“以为，认为”时，则用think of…as。e．g．
①I can’t think of his name.我想不起他的名字。
②You mustn’t think of him as being irresponsible.你不要以为他是一个不负责任的人。
③She gained confidence in herself as she thought the matter over．她好好想了想这件事，对自己有了信心。
④He put his whole heart into thinking up ways to improve the quality of heir Products．他把全部心思都用来想办法提高产品质量。
⑤His theory is so complicated that nobody can think it out．他的理论是那样复杂，没有一个人能把它搞清楚