do well to do something

(one) would do well to (do something)

One would benefit or fare better from, or be prudent or responsible by, doing some specific task or action. You would do well to show up to work on time tomorrow if you care to keep your job. You would do well to hire a lawyer now in case he decides to sue.
See also: well

do ˈwell to do something

be sensible or wise to do something: You’d do well to remember that I’m paying the bill.They did well to sell when the price was high.
See also: something, well