The Director-Composer Relationship
Once there has been established a working relationship between a director and a composer, as long as both parties are happy with this relationship, it will usually last for quite a while.
While this is beneficial and makes a few things easier once you’re in such a relationship, it makes it extra tricky for newcomers to get into the business. So if you’re just starting out, you should pick your battles very wisely. There is practically no point trying to contact established directors asking if they might have a job for you. Even if you think that you could do a better job than their current composers, in 99% of the cases they will stay with them. So any energy that you put into “replacing John Williams on Steven Spielberg’s movies” will be wasted.
A cleverer strategy would be to reach out to talented and promising newcomers who might become successful in the future. Of course at first you will not be scoring big movies but eventually this long term relationship might pay off. If you follow the careers of all established A-list composers, they have almost all been “dragged” to the big careers by one or a few directors who became more successful with every movie they made and who simply kept working with the same composer.