I saw a detection handler training tip on another website (www.caninesolution.com) which said "Take control when you have to, not because you want to."
For new K9 handlers, this is often one of the hardest things to do, which is to allow your dog to work without influencing him. Your detection dog is trained to search an area, locate a scent cone and work into source, and if properly trained, he won’t likely need your help. In fact, intervening will more than likely break his concentration and take his mind off of the problem he was solving and put it on you.
In detection, tracking, building searches, your dog is the one with the capability to solve the problem (nose) not you, and so you must let him work it out. Another tip on the website said, "Searches are 90% dog and 10% you." I agree. Keep out of his way, use your eyes to note areas he missed – your function is as his spotter – so you can make sure he makes a complete search of an area. Your function is not to solve the problem.
You need to work on known hides and known blank areas in training in order to learn your dog’s behavior and behavior changes when searching – if you do this you will soon develop the confidence to allow him to work uninfluenced.