Go online and read what you are allowed to bring in.
It is better for you to learn yourself than to get conflicting stories..
As stated, remove your sunglasses, have passports ready, answer questions directly and honestly.
If you are not sure you can bring something across and you have, then this is
the time to declare it. Likely they will just inform you of the laws and keep the item. If you don't declare it and they find it then you will more than likely be fined as well as the item seized.
We travel across borders quite often. Always be truthful.
Border patrol officers are not out to cause you misery. They want to be able to process you in a timely respectful way. If you do your homework then this helps them with their job and you get to continue your journey that much faster.