First and foremost, the groom should take care of their appearance. No matter what style it adheres to, clothing should be clean, neat and ironed. No need to wear a classic suit, if it is not a permanent article of clothing groom. Subsequently, it is still to emerge. So do not impersonate someone that the groom is not.
No need to overdo it with perfumes and deodorants. It is best to limit personal hygiene and clean clothes. If you really want, you can add a few drops of your favorite perfume, only so that it was unobtrusive.
Do you need gifts and pleasant surprises for the parents? If possible, they need. Maybe you should ask he loves mother of the bride. And suddenly she's allergic to flowers or she doesn't like sweets? To avoid unpleasant embarrassment that is prepared in advance. In your first meeting be limited to flowers or chocolates for mother of the bride. Expensive gifts do not give, but also with empty hands to come awkward.
You can bring something baked, mother of the groom, and so positioning, not only to himself but also to his mother. In absentia it will be respected and kindly tune to the next meeting. A gift to the father of the family to give not worth it. It is considered bad form. He feels awkward and bound his future son-in-law. The father should feel comfortable in your home and be the head of the family.
Not worth it to complain to the parents of his bride, to Express gratitude for what a wonderful daughter they have raised, if so. This approach will include the parents of the groom.
Also it is not necessary in the first day than to burden their future family. Something to ask, to consult. It is better to leave to another time will work out the mutual relationship and trust is established.
To inspire confidence in the parents of the bride need to speak the truth about himself, of course without further details. Look at the reaction of his bride, future father-in-law and mother-in-law, and to stop in time if necessary. Better during the interview be yourself. Show your best side, without unnecessary ostentation.
To answer the questions of the future in-laws. If any question has no definite answer, then you need to say so: "I don't know. Haven't decided yet. Think about it" is better than to blurt out nonsense, which will be evaluated by the groom as a person. A well-known fact that during a stressful situation, people may not understand what he was saying, then he may not even remember the conversation. While the surrounding people are offended by it, not knowing that he was excited.