feel one's way
Proceed cautiously, as in Until we know who we're dealing with, we'll have to feel our way. This expression alludes to groping by touch when one is unable to see. [Early 1600s] Also see feel for, def. 1.
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.