Trade is by far the best money maker in the game.

Build trader ships and get them to the 4 trade zones asap. With 4 traders in each zone and trade treatys you can easily make 2x as much in trade as you make in taxes. Allowing you to control Ireland by tax rather then occupation. Also Ireland you can build up as a military goverment so you can atleast build troops there faster and it will give you access to better troops. You will get less growth and less money from the region this way but in the long run it will pay off.

The first priority for me as Britian has been to take out the pirates in the two southern areas. This adds two regions to your empire and gets rid of the only real threat in the trade zones to your trade ships.

The pirates can be dealt with easily with about 6 line units or so. They have no forts and no land units so they only spawn milita type units to defend with. I sent my units over on a sloop going wide till I could come in close to avoid thier ships. After taking both locations the ships disappear. Removing them as a threat and ending that war. It also gives you a good deal of prestige as well as bloods your units in easy fights.

Those line units now form the backbone of your expiditionary forces. Where you go from there is up to you. Either stay in europe ( not a good idea IMHO) go to North America or go to india. Both India and North America are good choices as they are both rich areas. North America is my choice simply because with three regions I can get 13+ new regions. I also wait to hit North America and the indians will usally take florida from spain. Then I attack at florida move up to georgia then over to the nation to finish off those requirements. Leaving only New France to take care of. The Iraquoi Nation are good to have as allies as well.

Diplomacy there are several ways to go with this. Try to ally with everyone that will or try and drop the ones you would rather not be allied to. For example ally with prussia and sweden so you can drop any other alliances. Then drop those alliances and sue for peace. This in effect keeps you out of alot of european wars. But does mean you will have to declare war on France to get New France. You want as many trade partners as you can get and want to make sure you have no unused trade routes as that is just wasted money.

Your navy doesn't have to be overwhelming just good enough to keep your trade routes open and keep from being ganged up on. I used two fleets around the british isles. Moving one or the other into port as needed for repairs. With the priates taken out the small starting fleet in the American theater was enough to keep what I needed open or provide transport for my troops.

Technology is by far the biggest factor for britian as you can't really afford a huge army or even a huge navy off the bat. So what you have has to be good and strong. Trade for some technologies if you can. With the money will be making from trade routes you can eventually buy them off other people.