Perty much the same way we did on the Grand Canyon. While we usually used the radios (I retired in 2007) we would often change to hand signals, especially since the Trainmaster had a radio at home and we did not always want him to hear what we were up to !!!
I was fortunate enough to find a small booklet in a used book store many years ago .... published by a couple of railroaders in the 1940's or so, it shows photos of just about any hand signal you can think of. A couple of examples:
Skip Luke
Switchman (ret): Grand Canyon Railway;
Engineer (ret): Georgetown Loop RR Inc., Sumpter Valley Ry., Monticello & Sangamon Valley;
Dispatcher(ret): Illinois Central, White Pass & Yukon, Burlington Northern Ry.
Mariner, Musician, Miner