So I got one of these volt/amp meters from Amazon. Very inexpensive, under $20.
DROK 110V/220V 80V-300V/100A Digital AC Current Meter Volt Ammeter Gauge+Sense Transformer LED Dual Displayr Voltmeter Gauge+Current Sense transformer - Voltage Testers - Amazon.com
The trick is how to install it.
The photos tell most of the story. I have 50a service, and I put the current transformer around the neutral wire. It will read accurately when plugged into a 30a supply, which is really the only time I care about how many amps we're drawing.
I soldered longer leads onto the very short lead wires that came with the device.
It is important to realize that the current transformer leads must always be connected to the meter, or shorted together, if there is current flowing through the conductor that passes through the transformer. Dangerously high voltages will develop if this isn't done.
I'm not very good at metalworking but managed to cut a rectangular hole for the meter.