As others have indicated, the most usual place to indicate your preference with regard to your funeral arrangements is in your will. However (as I've stated above) it's still not legally binding on anyone. Further, there's the problem that many people seem to regard it as 'insensitive' to read a will until after the funeral, which means that the wishes might be seen too late.
However there's nothing to stop you carrying a card (of your own design), stating your wishes, in your purse or wallet. But once again, some people don't like to 'go through the belongings' of a dead person until after their funeral.
The best you can do is to consider who will be planning your funeral and to tell them your wishes directly. Even that doesn't always work though; my mother repeatedly told me that she hated the idea of 'being eaten by worms' and that she wanted to be cremated - unfortunately she never told my father, who had made all of the arrangements for interment before I knew about them.