Real Answer:
This one can feel intimidating, but don’t stress. Here’s how I did it:
Rabbinic letter: I got a letter from my community rabbi (Orthodox), stating I was born to a Jewish mother, including Hebrew names and background info.
Supporting docs: Some people also include bar/bat mitzvah certificates, synagogue membership, ketubahs (marriage contracts), or even family gravestone photos.
For converts: You’ll need the conversion certificate and full details about your beit din and process. The more “mainstream” your conversion (e.g., RCA, Beth Din of America, etc.), the smoother it usually goes.
Tip: If your rabbi isn't well-known internationally, the Jewish Agency might ask for more verification. Just stay in touch and respond quickly.