Hey, thanks for all the great advice. I sure didn't expect this to be so complicated.
I was specifically hoping to set up a portrait with short side lighting by holding the flash (with diffuser) out at arms length to one side with a reflector on the other. This would be intended to be used at little family get-togethers with impatient subjects who are mildly annoyed but indulgent of the crazy uncle with the ridiculous old camera. The key drivers would be simplicity, quickness and having little to carry. Basically, I want to get something much better than those typically gawdawful phone shots.
Edit to add: I want to keep the use of ttl metering which seems pretty reliable. I'm just not confident enough yet to be calculating flash exposure on the fly in these kinds of situations.