A few years after I retired from Boeing, I went to work for the local Transit Agency. The longest rigs they have are 40-footers (thankfully, none of the 65' articulated buses!) I'd never driven anything longer than our 26' Class C. One week driving 4 hours a day with the instructor, and I passed my CDL test. One week riding around on the buses as a passenger to learn the routes followed by one week driving with other drivers monitoring for a full shift and I was turned loose.
The tip I learned with the transit coaches, that has paid off very well now we have a 32' MH, is positioning for a turn. It's a similar trick whether turning left or right. You go straight ahead into the road you're turning into until the curb (right turn) or lane divider (left turn) is directly in line with your shoulder when you turn your head, then you crank the wheel over as quickly as possible, straightening up when you're in the new street. For a 40' rig, go about another 4' past that "over the shoulder" point.
When I first started, our agency was primarily a semi-rural one. During my first year, they got funding for two inter-city commuter services. I went from driving on country roads in a 30' bus to driving though Everett and Bellingham in 40-footers during rush hour.
Eventually, I got tired of the split shifts and getting up at 03:20 for the early expresses.