Raising funds for a film is never easy, no matter what level you're at. One can go the studio route, and simply sign over the project to the studio for a sum of money in order to see it made, not really caring what happens to it. Another method is pre-sales, where as a distributor would purchase the film from you with some stipulations as the creative process; i.e. actors they want in the project, directors, crew, story modifications, even locations. The most common method is the collaboration, where a handful of individuals have a project they very much care about and are fortunate enough to enter into a collaboration with a production company to bring the project to fruition. This avenue is the most versatile in terms of results; the company may fund the project, but have similar stipulations to a pre-sale, but on the other end of the spectrum they could also like the project so much as it is they'll fund it and step away until post-production and the rollout plan is ready to put into play. Also to keep in mind that this avenue could also end up anywhere in the middle, they may have actors they want to bring the project to, or simply a director they want to see take the helm but leave everything else intact; there's just no such thing as "the same formula" when it comes to film projects.
And then there is the rarest and most wonderful (if done properly) form of film funding; Private Investors. Currently, I am involved in 4 projects which have all been funded by private investors; individuals of person wealth or a group of them, that operate outside of the film world and are of the High Risk/High Reward persuasion. The 4 projects I am working with range from 500k to 2 Million, all private investors. However, private investments in film can be tricky, as Scott Macaulay has recently stated in his Film Maker Magazine blog:
"Private money is sometimes snarkily called “dumb money” because, presumably, non-industry investors are thought to be unmindful of the business’s economic underpinnings. I’d call such investment “idealistic money.” From my experience, investors know perfectly well the vicissitudes of film investing. They are people with high risk tolerances, but they are also people who expect that fairness and honest rules of business be present when they do invest. When a distribution promise is broken and a film is dumped to video, or when a minimum advance doesn’t even get paid, these people more often than not don’t get mad, and they usually don’t sue. It’s not worth their time and money. They just never invest in a film again." – Scott Macaulay
Scott's comment is 100 percent accurate in every way. I couldn't say it better myself. So moving on from that, if private funding is attained, then it is up to the Producers to be as responsible as possible. I'm often asked what a Producer "does" and until recently my answers have always been varied (as projects are never the same) and muddled. Now when asked, I reply that a Producer is most like a Chemist; A chemist is responsible for concocting the best formula for the desired outcome, and bring together all the elements that make that outcome possible. Knowing which elements are estimated to be desirable, yet also holding the artistic desires in the other hand.
Most commonly this occurs with actors; you may have a million dollars for your film, but that doesn't mean you need million dollar actors. Kelly Reichardt's "Wendy and Lucy" was a low budget film of small scope and scale and would not have the same impact it has if Sandra Bullock or Nicole Kidman had played Wendy. A good producer would know this, and if they didn't, a good director would inform them of it.
The project that I wrote, "Our Last Days As Children" (http://www.ourlastdaysaschildren.com/) is a character driven story with a very outspoken story. Our aim is not a blockbuster like The Dark Knight or American Gangster, its just not that kind of film. Its scope and scale is more on par with Heights, The Savages, Half Nelson and Once, and we hope that it will be as well received. While some of these films had very talented and very well known actors, the films themselves had modest goals and the production teams knew what kind of films they had (which is always the toughest to gauge).
For "Our Last Days As Children", which is an ensemble film, we have chosen to work with mostly new faces. However, we are smart enough to know that to attain the right distribution and seem attractive to more festivals, we do need a few recognizable actors, so we have attached 3 recognizable actors for supporting roles, and are targeting two more wider known actors for two of the main characters. With that in mind, we have to then make sure that these actors fit the characters; can they play these characters? do the actors have the proper demeanor to provoke the right emotions? are they modest enough to work with a younger production team? do they believe in the project itself? These questions are amazingly difficult to answer, and finding the right actors that fit these criteria can be difficult, but not impossible.
Once you've made your choices, the task then becomes making sure your investors are comfortable with them, unless you had these elements before you came to these investors. There is no all around strategy for this as every project has different circumstances, but presenting your investors with as much information on the actors as possible as well as their resume is a pretty good place to start, and sometimes it may be as far as you need to go.