There were two key themes of French-German trade in the 19th century. One was the iron and steel trade that tended eastward, toward Germany, and the other was the textile/apparel trade that trended west toward France. The Alsace-Lorraine was important to both sets of trade.
Regarding the iron and steel trade, France was long on iron and short of coal. Germany had little iron and a lot of coal. Germany started in a better position because it takes several tons of coal (fuel) to "smelt" one ton of iron. So it made more sense for Germany to import iron from France (rather than France to import coal from Germany). Germany was in an even better position when she captured France's Lorraine in 1871, a major source of iron, at which time this source became "domestic" rather than "imported." The resulting strength of the steel industry in Germany supported growth in related industries such as banking, chemicals, electrical goods, and railroads.
The industrial development of France moved in the other direction; toward luxury consumer goods such as wines, cheeses, and apparel. Key to the latter was the textile industry of Alsace, which was French until 1871, and German thereafter (until 1918), from where France imported many of her textiles.
One can get an idea of the different emphases of the French and Germany economies by looking at the export companies that were founded around the mid-19th century. French companies founded at this time include luxury goods manufacturers, Hermes and Louis Vuitton. German companies founded around that time included Siemens, the "GE" of Germany, and BASF and Bayer, the chemical companies.
The German industrialization model was far closer to Britain's, with Germany (and America) overtaking, then surpassing Britain in steel, chemicals, and electrical goods by 1915. Germany was comparable to Britain in railroads, and somewhat weaker in finance. But it competed with Britain and America in providing capital goods to modernizing European countries in the eastern and southern parts of the continent.
France had a narrow set of goods, but its predominance in luxury goods was more global (even perhaps, to this day). That's because it had fewer directly competitors. In Renaissance times, "Italy" (or Italian states) competed with France in the luxury goods area (and Italy does so today), but around 1900, France had left Italy far behind, at least until Italy caught up industrially in the late 20th century.
Unlike the UK, Germany's colonial empire hardly impacted its trade position, and France's barely more. Germany's main colonies such as German East Africa (modern Tanzania), German West Africa (Cameroons), and German Southwest Africa (Namibia), were established in the late 19th century (1880s), and were not particularly rich. France's colonial claim to fame was Algeria, colonized around 1830 (other possessions in Africa and Indochina came much later). Neither of them had any colonies like Britain's India, which exported opium to China and cotton to Britain, South Africa, with its wealth of gold and diamonds, or Australia, one of the world's richest countries per capita, despite an agriculture based economy. All of these British colonies had been established earlier than the late 19th century.