I would choose to bring a lot of silver to the past.
No matter where, money is the most practical thing, right, only they have money, can eat and wear warm, live comfortably. And silver, in ancient times, especially valuable and universal, more is better.
For the modern cell phone and so on, I think there is not much use to bring it over there, one has no signal, and the second is useless without electricity. Maybe it will also be treated as a demon by the ancients, I am a powerless woman can not resist. So ah, or silver is the most practical.