For my first free write, I can tell, that an important point that I have seen since the first episode after watched the ones for class and now the new Doctors is the evolution of technology, including both the environmental and villains.
It can be seen in the first episode that the fights are with wood swords, but later on, people will have different types of weapons such as guns, knives and other out of universe weapons brought it by the villains. Also, the villains have some kind of technological aspects such as in “The Mind robber” the Master is a machine, while the army are robots which looks like toys. Also, other kinds of robots appear in the “Pyramids of Mars”. And I also came out with the idea that there are many types of technology, it can be seen in the “Green Death” when the maggot situation happened, I think that the BBC wanted to show also how science was developing.
Later on, in other episodes, the signal that show us that technology was developing was when the episodes start appearing in color. Also depending on where they go, there were cars and more fancy things. They showed as well cities and factories, which differs in all episodes.
The most important of all the show, I think it would be the TARDIS. It is the same in all episodes but some small changes had been made. Now, while we are watching the new Doctors we will see even more differences and improvements of the villains and things around in the environment.