Clues could also be culled from the length of home inspection. Ask your inspector how long it usually takes for him to complete a job. Most qualified home inspectors do the job in more than three hours. If the inspector intends to complete the task in mere 90 minutes, something is really wrong with him. You are not inviting a person to just come and appreciate your home. Remember, you are inviting (and paying) a home inspector who should meticulously inspect your house.
Some inspectors are also vocal in recommending repair and maintenance contractors long before actually inspecting your house. Stay away from those inspectors. They are obviously just trying to make business with you. How sure could you be that the inspector would not identify problems just so you could hire his recommended contractor? For all you know, that inspector might be into a partnership or commission deal with a contractor.
A qualified home inspector is not asking for re-inspection charges. The initial inspection might require several repairs. After the repair has been completed, home inspection must resume finding out if the task was successful in eliminating possible problems. If the inspector tells you his services does not cover such re-inspection, drop him.
You should also prefer a home inspector who agrees to have you be around or be with him during the inspection process. Unqualified inspectors are afraid that clients might discover that they are not actually inspecting accurately and systematically. See, it could be easy finding the best inspectors around.