I co-wrote a border search guide for EFF some years ago. I was very interested in finding clever technical approaches but I later ended up feeling that I hadn't given enough thought to the overall threat model questions (even though the guide did address them, perhaps even somewhat usefully). The big picture problem is that the agents performing the searches have an enormous amount of power in terms of potentially se…
Like, get a cheap phone, install the bare minimum stuff you need for travel.
For extra safety, before returning home wipe it and just put back the exact apps you need for moving around (e.g.: ride hailing app).
Same thing with laptops, tablets, etc.