Looney Pilot - the first 20 hours or so of my training were in a C172 in Canada and I was taught to bring the carb heat out to Hot as part of downwind checks and leave it Hot for the rest of the circuit - it worked for me. For a go around, the carb heat and throttle are just see-sawed, aiming to have carb heat out whenever less than 2k rpm and vice versa.
When I returned to UK to finish off, it was a bit of a surprise when I was taught to only bring carb heat out on base leg as part of the approach config and to put it in again on finals. It was even more of a surprise when after flying for 5 years and doing a check ride for the first time at Fife, my instructor reminded me to do the CRAP checks on finals. This got a puzzled look from the left seat and he explained:
C Carb Heat Cold
R Runway Clear
A Approach Stabilised
P Permission to Land
I had honestly never been taught those (but it seems from other threads that most in the UK have been). I was also fooled by a TRPACER mnemonic!