What do yall look for when you consider a good spot to drift-fish? Underwater structure? River channels? Depth?? I'm interested in catching big blue's but don't really know much about catfishing from a boat.

I prefer mud flats around 13ft of water in summer....6 to 10ft in when water is cold. When water is really cold, deep channels.

For me when I got better electronics it changed how I drift, I like setting a drift over an area that I have seen fish, humps and channels of course but also flats as has been said, I only purposely avoid stumps or timber for obvious reasons.
You are gonna loose some tackle but i loose it sometimes anchored also.
I like drifting, some don't.
Its just another tool you can use when you go fishing.

Thanks for the responses

I drive my boat against the wind, while looking at my sonar. I find a large school of blue cats and pass the school of blues. Turn my boat Then throw out drift socks and fishing lines and drift across the school of blue cats. Find them, pass them then drift fish over them.