I drain my lines and shut off the heat too. And I've made ALL of the mistakes.
#1 The first year I blew out the lines with 120 PSI air. It literally "blew out the lines!" It blew the joints apart!
#2 I bought 2 ice maker solenoids before finding out how to trick the ice maker into cycling. (You take out all the ice and wait for the ice maker to hiss with air.)
#3 You have to add the antifreeze into the holding tank of the toilet to get rid of that last inch of water in there.
#4 Outdoor "freeze proof" faucets need drained too.
#5 The compressor has a drain valve on the air tank to get the water out of there.
The only thing that kept me going after all those flubs was the belief "If there isn't any water nothing is going to freeze!"
One year the kitchen floor buckled. I tracked it back to a leaky drain under the kitchen sink with water seeping into the sub floor. I fixed the leak. When the house warmed up the buckling went down. So I guess it was a good thing. It kept my kitchen floor from rotting out.