Others have implied this, but to be very clear:

DO NOT pack the iPhones, laptop, iPad, cameras, watches, jewelry (your own or gifts) or anything else valuable in your checked baggage! The TSA will x-ray your checked bags so they will see electronics or jewelry, and they can open (or destroy) your locks. Also, the airlines will not take responsibility for these if they are in checked baggage.

I had a little drawstring bag - with two pairs of (inexpensive) earrings and a simple silver chain - stolen from my checked bag while flying SYD-SIN-AMS. It was inside a zippered makeup bag inside a zippered compartment of the suitcase, and nothing else was disrupted, so clearly the security agents at either SYD or SIN x-rayed the bag and knew where to look. Now I put all my jewelry in my carry-on.

All the electronics and jewelry will have to go into your carry-on. The only limits are the limits on the number of carry-on bags, and the weight and size of those bags. (You might be allowed a separate camera case; check with your airline.) Note that you cannot take extra carry-on bags just because you have a lot of valuable things. If you cannot get all these things into your carry-on bag and be under the weight/size limit, you will need to find some other way (can another family member take some of them, or can you Fedex them to your destination)?

Good luck.