YMMV with this advice. Sometimes you have the opportunity to under promise and then over deliver. A delightful surprise such as something they didn't expect to

YMMV with this advice. Sometimes you have the opportunity to under promise and then over deliver. A delightful surprise such as something they didn't expect to get done or by a certain date can make your work seem more impactful to clients and management. However, this is very situational and you risk falling into a trap where they begin expecting too much from you if you purposely do this for everything you do.