draw in (one's) horns
To act more cautiously than one did before. I just got this quarter's budget report, and we definitely need to draw in our horns and spend less going forward.
draw in one's horns and pull in one's horns
Fig. to back down from a fight. For a minute it looked like they were gonna start sluggin' each other, but then they drew in their horns. We tried to calm him down and get him to pull in his horns.
draw (or pull) in your horns
become less assertive or ambitious; draw back. The image here is of a snail drawing in its retractile tentacles when disturbed.
1991 Paul Grescoe Flesh Wound Hollywood's major studios were pulling in their horns in the wake of a disastrous Christmas season.
draw/pull in your ˈhorns
start being more careful in your behaviour, especially by spending less money than before: After making huge losses, the company had to draw in its horns by cancelling some major projects.