I can share my experience so far with a 2018 2.5 Excel Hybrid AWD. I have only done 2000 miles from new so the engine may have been a bit tight for part of that but am getting around the 40mpg mark in general driving which includes short (2 mile) journeys where the engine will be in warm-up mode, therefore using more fuel.
I decided to experiment with 97Ron petrol to see if the 2.5 could make use of better low down torque, but have not done enough miles for any real conclusions. Interestingly while on BP 97Ron, on a 20 mile journey which included the hills around Bath in general traffic, the computer showed 54mpg, and I have had 50 on a 10 mile run, so it looks interesting. I will admit I am no longer a boy racer, that was many years ago in my MGA, but I don't dawdle.
You asked for driving style pointers, the only ones I can offer are :
1 - it's all down to your right foot, use the Hybrid System Indicator dial (it's like using the old manifold vacuum gauge) to tell you if you are using more throttle than necessary, try to keep in the sweet spot of the lower half of the Econ range, dramatic driving burns fuel.
2 - my dealer advised me that the Eco and Sport buttons don't do anything that sensible use of your right foot can't, especially if you use the six selectable ratios if you need something special.
3 - anticipate what the vehicle in front is liable to do so you can substitute regenerative braking for standing on the anchors.
4 - you can manipulate the engine control software , especially in town or at constant speed, by easing back on the throttle until the car goes into regeneration mode, then lightly open the throttle which will put it into battery driven mode. If more power is needed the engine will start automatically, but you're still on light throttle.
Always bear in mind that a hybrid makes its money by turning momentum into battery charge instead of disk brake heat. Don't be scared to use the car on battery, that's what saves you money. Running with a constantly full battery is unnecessary and means there can be no regeneration. The electronics will always cut in to charge the battery if it gets too discharged.
I hope this is of some use to you, they are purely my own observations and I hope you enjoy your new vehicle as much as I am mine.