Ok, the titles a tease. One can't really guarantee anything. However with some common sense, correctly set expectations and a good inspector, you should end up with a reasonably accurate inspection. Here are some tips to make that happen.

Education- Clients need to understand the inspection process. That education starts when the REALTOR describes the buying process. First step is picking the inspector. Some sites recommend against using a REALTOR referred inspector. If your clients doesn't trust your  recommendation, you got bigger problem and you need to regain their trust. Secondly, you has more contact with home inspectors than anyone else. We already know that your  not going to give the client the pickiest inspector of the bunch or the lackey. In between there are a good group of inspectors. Most REALTORs will give the client three picks, encourage the client call them and book with the one they  like the best. There are a ton of websites that will give the client good questions to identify the "best" inspector.

Set Expectations - The client needs to understand what the inspection is and isn't. It is a visual inspection - its not exhaustive. Visual means we are looking at things - no X-Ray vision. If the issue is concealed we can't report it. Not exhaustive means that we don't  tear apart everything  as if we were experts. The except is removing the electrical panel cover and furnace cover, we don't tear things apart.  Accessibility means we need to be able to safely access an area. Wet or steeply pitched roofs are not accessible, Insulated attics with no walk-boards are not accessible. Safety is important. Some inspectors will walk attic trusses, some of those same inspectors will miss the beam and fall through the attic. I tell my customers my goal is to identify BIG issues. A big issue is something that will cost them $1,000 or more to repair. If a see something smaller I will usually also report it but I focus on BIG items.

What We are - Home Inspectors are generalists. The best analogy is comparing a family practitioner doctor and a orthopedics doctor. A family doctor knows about broken bones, can identify them but refers the repairs out to an expert, the orthopedics guy. A home inspector knows all about  different aspects of a home and can identify the issues but ultimately refers the final diagnosis and repair out to the experts.

Make sure the house is ready for the inspections - Short sale or foreclosure properties frequently don't have all the utilities on. An inspector can't do a complete job is the electric, gas or water are not turned on. Please make sure everything is on.  I had a REALTOR tell the client that of course I would come back to finish the inspection when the gas was turned on. When I informed her that there would be a charge to come back she appeared surprised. I quietly informed her that I was here to do a complete inspection and that it was through no fault of mine that the gas was off. To come back (it was 30 miles from my office) I would be driving 1 hour round trip and most likely 1 hour at the property. 2 hours time plus vehicle costs (I drive an SUV!)

Attend the inspection - I prefer that clients attend my inspections and appreciate when the REALTOR attends. Clients get to see the home through my eyes, interactively ask questions and get a sense of what the home is and isn't. When the REALTOR is present they can answer questions that are outside my domain such as easements, shared well agreements, inspection contingency, what to ask the seller to fix etc. Some clients will start to panic as I point things out. Remember we are paid to identify issues with the house. Although I can help keep things in perspective, I don't have the same relationship with the client that the REALTOR has. Some REALTORs don't think its a good use of their time to attend the inspection. I disagree, if the deal goes south because the client panics at the inspection and decides to walk, was it worth the two hours you gained to do something else?

Uninformed clients will ask whether the home passed the inspection. From my perspective houses don't pass or fail. It's all in the eyes of the buyer. What is a diamond in the rough to one client, is a money pit to another. Another question is "would you buy this house?" I look at functionality and condition. I don't look at rooms sizes, decor, flow and location. I always have to delicately answer this question.

Review the entire report    - Read the whole report. As a courtesy I provide a summary but no all inspector do and not all the detail goes into the summary. Its just highlights, the report has the details. When you spending this much to purchase a home you really want to look at all the details. Something may jump out at you that wasn't that important from the inspectors perspective.

Ask questions - My service doesn't end when I've delivered the report. If you have a questions, call or email your inspector. Find something at final walk-through or on move-in day. Call the inspector. This helps identify and eliminate issues before they become big problems.