Rushing the trade spots was the first thing I did in the last campaign I played, started and stopped on Saturday. I had all but one of the trade spots in Brazil and both coasts of Africa. Rushed my initial sloops and brigs to those spots and held them until the Indiamen were built 2 turns later. UP and Marathas beat me to Indonesia.

And then once I had those spots, nobody every challenged me for them, not even pirates. Single Indiamen sitting there without any escort in the theater.... nothing to see here, move along Blackbeard, thank you. +16000 per turn. Millions of elephants died per turn for all the ivory I was shipping out of Africa. I could've built a life-size replica of the moon outta the stuff.
With UP it isn't uncommon to bring in 25-30k a turn from trade which pretty much means you dominate the global economy, especially given that UP is tightly alllied with GB and anyone who tries to go to war with you ends up getting whiped on the high seas by the Royal Navy.