For me, the most important ingredient is the canned anchovies and Dijon mustard. That is the fundamental.
After that, be creative. I like to add a a small amount of olive oil and maybe a few drops of hot sauce. My favorite topping is a raw egg yolk.
When you make a good steak tartare, serve it with a good crusty French baguette. If you don't have acesss to good French bread, eat it with your best quality bread you can find.
