Lots of mountain ranges. Preferably with lots of small fertile river valleys and lakes separated by really impenetrable mountains.
I reckon modern Europe is more composed of small states than in the 19th century, mostly because of Eastern Europe and the Balkans. For most of its history, India has not been a unified country; the norm has usually been for some sort of small empire in the northern river valleys alongside numerous smaller regional states.
http://en.wikipedia.org/wiki/Middle_kingdoms_of_IndiaChina is somewhat similar in that there were often numerous regional polities. The "Chinese" government sometimes exercised nominal rule over them, but was often unable to project power much or manage their affairs too heavily; this was the case with Tibet in the Ming and Qing eras, for example. And in addition to the splits that often occured in China itself, much of southern and western China was composed of independent states that got sucked into China fairly recently, like Dali. A lot of what happens in China is Chinese civilization historically focused on the two main rivers and the coast, and penetrated into the southeastern mountains, but took more time to dominate the various ethnic groups in the west and southwestern mountains. Or what you'll get is a period of fragmentation, which quickly coalesces into a new empire in the North China Plain due to the lack of geographical barriers, which then begins to reach out into the Chinese periphery again.
Another way to look at it is that empires are difficult and expensive to manage. It takes a lot of sophisticated communications, bureaucracy, and energy to project power over a distant region for a long time. And the modern norm of cohesive, stable large states is somewhat anomalous, made possible by advanced communications and information technology, motorized transport, and firearms. Relative cultural homogeneity helps, and an explicit process of "nationalization" of the population helps.
In the premodern era, it's relatively easy to amass a large group of warriors and send them off, since conquering warriors can survive on pillage rather than your own economic base, but this doesn't work as well to dominate a region once conquered. Most empires last only a century or so before burning out, only with significant "organizational technology" do they survive for long. In the early industrial timeframe, it seems likely that a state that has just invented machine guns and railroads would use them to try and take over the others.