What all factors contributed to successful colonization of Asia and Africa by European countries in 18th and 19th century? And, why England was more successful than the other European countries?
First I'll suggest to read the books Age of Capital and Age of Empire of Eric Hobsbawm.
Now a small list of factors:
1. Industrialization. Because you need new markets and access to resources.
2. Population grow. Industrialization improves agricultural yield thanks to machines and canalization works, that increases the population and the pressure to find new lands.
3. Technology and sanitation. I put both things together because the improvement of knowledge on medicine helped to prevent diseases. This is particularly important in the case of Africa, where europeans died of malaria in great numbers. Besides, the weapons given by the industry gave to the european countries a huge advantage over the nations they subdued.
Now, why England was more successful than other countries? Basically because their industrialization was earlier, therefore they had the urge to search for new markets before anyone else. Besides, the recent independence of United States removed from the map the most important overseas market for England, that's why the had to go for new colonies. Finally, they were the most important naval power, which is required to launch military raids and invasions in other lands.
Each country searchs for colonies and new markets when they reach industrialization and they have a surplus.