Make a thorough assessment of how you look in front of a full-length mirror. And don't hesitate to get a second opinion. Check not just for fashion sense but also for fit. Nothing sends a worse message than a poorly tailored jacket. One common offense is sleeves that hide your hands.
Hands speak worlds about capability.
They also reinforce your words. Hiding them can send a subtle message of incompetence. The jacket sleeve end at the middle of your wrist bone, with the shirt sleeve extending three eighths of an inch beyond. Since almost everyone has one arm longer than the other, make sure the tailor checks the length of both sleeves. If you are not wearing a long-sleeved blouse or shirt under a sports coat, the jacket length should extend to the end of the wrist bone.