Here are some tips on how to present a house during a viewing:

1. Start cleaning your house so you give a homely and warm feeling for the viewers.

2. Start checking if the windows need cleaning and make sure the lights look good as new. 

3. First impressions are the most important as the buyer are already making decisions about the house.

4. Maybe a diffuser would help!

5. Make sure the outdoor space will give a good vibe when viewers look at it.

6. You may not these people, so you should give a friendly, professional and accommodating feeling towards the viewers. 

Hope these tips help!