think outside the box

think outside the box (to develop ideas that are different and unusual) — мыслить нестандартно, мыслить творчески; мыслить оригинально (~ латеральное мышление); ~ уйти с проторенных дорог; отойти от традиционного подхода, взгляда, способа мышления

Example 1: We need to think outside the box if we are going to come up with something really new.

Example 2: These guys are incredibly creative — they really know how to think out of the box.

Usage notes: sometimes used with verbs other than think:

Example: You need to look outside the box and see what you can come up with.

A person who thinks outside the box is the opposite of someone who is square.

Etymology: based on the idea that limiting your thoughts is like thinking inside a box which can contain only a certain number of ideas (СDAmId)

cf
[push the envelope]