The larger the airplane, generally the more stable in terms of mass an inertia. The larger the airplane, the greater the concept of mass management comes into play. The greater the need for stabilized operations such as approaches, early corrections, and small corrections.
When I started flying ag, time was money, and we stayed busy. We'd fly nearly to the runway at low level, roll into a steep turn to align with the runway while retarding power to idle, slow down so quickly it threw us forward in the seat, and touch down as we rolled out of the turn. When I began flying tubojet airplanes and big airplanes, I found that slowing down early, much farther away, and getting configured early was the key to making things work out.
In a small airplane, problems can often be handled on power alone, one can tolerate quick control inputs, and errors are often soon apparent. In a large airplane, power inputs must be planned in advance, and one may have to lead the power; put in more than required then take some back out, to achieve the same thing, make smaller, slower control inputs...and errors may take some time to show up. If not caught early, they may grow to the point recovery is difficult or even impossible (getting slow on an approach, for example, when heavy).
Probably one of the most important things to bear in mind after mass management, I think, is that a cockpit is a cockpit. There's a lot of airpalne beneath you and behind you, but the same principles apply in a Classic B747 that apply in a Cessna 172...the difference is that you can get away with bad habits more in the 172. Things don't happen fast, but should be done methodically, relying on procedure, coordination, other crewmembers, and the checklist.
The single biggest two helps to flying a big airplane, in my opinion; know the airplane and learn to work as a team. You can never learn enough about the airplane; systems, procedures, etc. You will never stop learning to work with others as you experience different skill levels, mentalities, backgrounds, experience, etc, among those who share the cockpit with you. What formerly was second nature and something you handled yourself suddenly becomes a subdivided task in which everyone plays a part. Others in the cockpit, be it a captain or first officer, or flight engineer, are people, professionals, and like your instruments and controls, required equipment and a part of the airplane. Learning a large airplane is as much about learning to coordinate your efforts with everyone else as it is about manipulating controls or learning systems.
Good luck!