By Zero Expectations, I mean that I don't expect the film to be any good, this way if I enjoy it, then it must truly be good and if I feel the film is no good, it must be truly terrible because I didn't expect it to be good, but it still disappointed me and fell below that.
Before deciding on watching a film, I usually watch a trailer of a film and if it looks interesting I go see it. For example, Yamla Pagla Deewana and Dabangg had such powerful trailers that I immediately wanted to go see them. When I watched the trailers of 3 Idiots, it didn't excite me like Yamla Pagla Deewana or Dabangg, but it was able to convince me enough to give it a try. Before watching 3 Idiots I was fairly sure it would disappoint me, but to my surprise, I rather enjoyed the film and have watched it many time since then.
Over the years I have seen thousands of films in several languages (Hindi, English, Gujarati, Marathi, German, Spanish, Italian, French, etc.) so, I'm not looking for anything original, all I expect from films today is that they will entertain me for the 2-2.5 hours I'm there. There was nothing original about the Munna Bhai Series, Yamla Pagla Deewana, Dabangg, Main Hoon Na, Sholay, Ready, Once Upon A Time In Mumbai, or Bodyguard, but they did entertain the audience for 2-2.5 hours.
There are several ways filmmakers lure the audience into a movie theater. The most common is probably the music, it's commonly believed that if your film has hit music half the battle is won - hit music will compel the audience to buy a ticket.
From the beginning of Bollywood 'till about 10 years ago, it didn't matter how good or bad a film was, one thing you were guaranteed was a hit soundtrack. Today, because music has become a marketing tool a hit soundtrack is very rare. Now, a film usually has just one song or an item number which become the rage and sell the film to its audience (like Chammak Challo, Sheela Ki Jawani or Character Dheela). Very rarely do we see a complete soundtrack which is enjoyable from the first song to the last (ie. Veer-Zaara, Dabangg, 3 Idiots or Lagaan).
Seeing as many films as I have, I understand what's out there and when I write I know what I can't use. For example, I know it's not a good idea to use sex jokes, fat jokes or race jokes because the audience has heard them all, unless I can present them in a new way there really is no point, especially in the "politically correct" world of today. As a writer it is your responsibility to give the audience what they want... Entertainment! Whether it's through entertaining dialogue, comic scenes or action sequences that's up to you. When the audience leaves a movie theater they should feel that the film has exceeded their expectations, then and only then has a filmmaker been able to reach his audience.