take pains over

take (great) pains over (something)

To expend a lot of time, effort, and care doing something. Your tutor took great pains over your instruction, but it's obvious that you've totally wasted his time and our money! It's clear that the owners have taken great pains over the interior design of the new restaurant. My grandmother always took pains over her appearance throughout her life, so losing her hair during her cancer treatment was especially difficult for her.
See also: over, pain, take
Farlex Dictionary of Idioms.

take pains over something

Fig. to deal with something with great care. (See also take pains with someone or something.) She certainly takes pains over her work. You will have to take pains over this if you want it to be done right.
See also: over, pain, take
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • take (great) pains over (something)
  • take (great) pains with (something)
  • take pains with
  • take pains with something/to do something
  • take (great) pains (to do something)
  • take pains
  • take pains, to
  • expend
  • expend (something) for (something)
  • expend for