Yes, going with two or three colonies is probably the easiest approach to winning. Here's something I wrote to a friend who was having trouble at Explorer. (I don't claim that any of this is original to me!!!)
Let's see if I can give you some ideas and a suggested strategy for Explorer level. I've been playing at Conquistador and Governor, and things do indeed get harder, but let's go with a basic strategy that should work at many levels. After you have a victory at Explorer you can explore alternate strategies (and of course you can ignore this one!!) Okay, let's go, remembering that there are many other ways:
Basic Keys: Win fast with early scouting, only two or three Towns, and late Liberty Bells.
Faction and Leader: perhaps the best choice is the Dutch with Van der Donck as that gives you a merchantman and cuts in half the rate of tax increases. (With John Adams, be cautious to avoid premature generation of Liberty Bells. Champlain is a poor choice.) Besides, it would seem that the Dutch are your natural choice!
Towns: Starting location isn't as critical as you might think, but ideally one city is on the coast with lots of food. You want to have about two finished exports (better yet, silver), but you probably won't have time or need for factories. I want the second (and third) city inland leaving the one port as the target of the REF. Ideally, build next to an inland forested hill (and don't cut down those trees), this can be your defensive base.
Scouting: Get a scout ASAP. Sell your tools to the nearest natives and send the former pioneer out on foot. At Explorer you can safely--if nervously--sell your starting guns for starting capital. (I have yet to get burned selling them at Conquistador.) Have your "non-colonist" start scouting while you scurry back to Europe to grab a seasoned scout, or if none are available grab whoever showed up on the docks and convert them right there to a scout. Send the scout off in the other direction. When you run out of land ship your scout to another land mass, preferably one without European colonists (and their scouts). The goal of course is to visit as many villages as possible to get money and treasure. Unless you find a lot of treasure you probably shouldn't pay for a galleon since you have to find 6,000-worth to break even compared to giving the King his piece of the action. [Treasures on other land masses are problematic, since you don't have a town there for the King's galleons. If you're pumping out goods then a galleon may have a dual purpose.]
Cash: Use your cash to get your economy humming quickly, then build (or hurry) a school and college. Buy an Elder Statesman (and cheer if one turns up on the docks). Use the rest of the money to buy a bunch of cannon (6-10), and enough guns and horses to equip 10-15 dragoons (plus a token garrison--one soldier--in each town).
Education: Statesmen, only Statesmen. Put your first Statesman in the town with the college then slap three colonists in there, making sure that you have enough cash at the right time to pay for each graduation. [That's one of my favorite mistakes!] Then put in two more students to give you the six Elder Statesmen that you need for two cities. If you nine Statesmen you will probably have to buy some, and that's a good reason to limit yourself to two towns.
Meanwhile...build printing presses and newspapers in all your towns (and build roads in all the tiles within two of the coast).
Once you have the elements in place (Statesmen, Newspapers, Cannon, Guns, and Horses), put the Statesmen in the Town Halls. You will go rapidly to 50% and declare independence while the REF is small, perhaps 10 regulars, 10 dragoons, and 8 artillery. [If sentiment is rising slowly you can dismiss surplus population, I stop accepting converts (dismiss them) late in the game.]
Once you declare, convert almost all your population to dragoons and pull them inland, one or two tiles away from your coastal city. If the REF takes that city they are sitting ducks for your counterattack, but you can handle the ones that land elsewhere. You should wipe out each wave as they land, or perhaps one turn later for stragglers.
Rinse, repeat.
This should work on any map size, probably even in a Quick game (though I've never played at Quick). It may fail if you have only a bunch of islands where the scout can't make enough money.
Give it a try and let me know how it works.
-- Ed
Oh, there's a trick that makes it even easier: initially build Political Points and defer everything else until you get Pedro Alvares Cabral (-50% Travel Time to Europe) and Peter Minuit (-25% Cost of Recruiting Units). It won't take long (even at Revolutionary!) and gives you a leg up.
Yet another: buy guns and horses and sell them to the natives until they run out of cash, that will give you a lot of quick cash to accelerate your development. If you do this be sure to build stockades and keep a garrison in each town. [Don't try this with hyper-aggressive tribes like the Inca, the Aztecs, and the Apache...unless they are close to other Europeans, preferably on a different land mass!]
