As a poor filmmaker you have one resource to leverage.... TIME. Time is your biggest asset!
You can spend time in planning, pre-production, previz rehearsals etc.. this will make your end product look like a bigger production.
Yes! I second that.
Some other things that go a long way towards making your ultra-low/no budget movie look more expensive:
1. Actors. Get really good actors who know what they are doing. Cast the best actors you can find/afford. A good performance from a charasmatic, interesting actor can really elevate a film. Likewise, a boring or poor performances can drag an otherwise solid film right down.
2. Dialog issues.
a. Try to make your dialog as sparse as possible.
b. If you want to have a dialog driven film, find the most interesting ways to shoot that dialog. Woody Allen's films are very talk driven, sometimes he has seven minute conversations. However, watch closely at how he films them.
Here is a four minute conversation in Crimes and Misdemeanors. It is only two shots I think, but watch how he stages it. It is almost never boring.
https://www.youtube.com/watch?v=uZQ5qKpUk08
Many low-budget/first time filmmakers have these long conversations take place in a static, medium two shot at a dinner table or something. Which leads me to:
c. If you do have two people
seated, having a conversation that is longer than, say, a page of dialogue, then it is impossible to shoot
too much coverage. Make sure you have an establishing shot, a medium two shot, over the shoulders, medium close, extreme close, etc. Also, don't forget inserts - closeups of hands pouring the wine, or passing the business card across the table.
Of course, time won't allow you to get all of these, but you should try. A second camera helped us greatly on a short we made that had a long dialogue scene at restaraunt. Which reminds me, don't forget to get reaction shots and closeups of the waitress or waiter.
This will allow you, in editing, to give the viewer many different things to look at during the conversation.