The lowest fare on the screen is not always the cheapest trip once real life intervenes. The rules attached to a ticket decide what a change or cancellation will cost you, and for business travel that flexibility often matters more than the headline price.
Before booking, check what the fare allows: whether changes are permitted, what they cost, and whether a bag is included. A slightly higher fare that lets you move a flight can be far cheaper than a bargain ticket you cannot touch when the meeting shifts.
Match the fare to the certainty of the trip. Lock in the cheapest option for plans that will not move, and pay for flexibility when the schedule is still in play.