Assassin's Creed 4 gameplay is some of the best the series has ever seen. Nearly every detail has been used to its greatest advantage, even in the ship battles the pirate game is known for.
Captain Edward Kenway is a British privateer whose primary aim is to get rich and return home with money and respect, but his path to that end is a long one. Achieving full "synchronization" will take time, and lots of trial and error. Assasssin's Creed 4 is a tough game, but its difficulty leaves just enough room for error that persistence and experimentation will get you through the game.
Getting rich with Assassin's Creed 4's gameplay can take a while at first, but if you do it right, you will end up with more money than you need.
Learn to pickpocket while walking, aiming for the better dressed citizens. This is the fastest way to earn money early in the game, and it will inevitably teach you how to deal with multiple guards. You will probably never need the high-end swords, but you should definitely invest in the best pistol on the list. You will use that gun a lot, especially when you're surrounded by some of the more difficult guards. Also, loot every guard you possibly can.
When you get your wrist blades, equip them almost immediately and start attacking groups of guards regularly. Save as much money as you can for ship upgrades because naval battles are where the real money is earned.
Hunting can also be a real money saver because every animal you kill earns you a bone you can use for special darts and their pelts can be crafted into upgrades to let you carry more stuff and take more damage.
As you sail around, look for ships that are already on fire and (usually) deserted, and start looting as much from them as you can quickly. They all have a timer that will kill you if you stay on the ship too long. This is one place where the Assassin's Creed 4 gameplay could end up making things tricky because you'll need to pop out of "stealth leaning" as soon as it happens. That timer doesn't stop just because the game doesn't know what you're trying to do.
Also look for floating cargo. This is basically the easiest way to get free money in the game because sugar and rum will be your highest sources of income until you power up your ship.
After you have upgraded your ship as far as you can, the real cash flow can begin. It is not automated like it was in Assassin's Creed 2, so you will need to tell your fleet where to go every time. Search everywhere for ship upgrade plans, especially after getting the diving bell at about the halfway point. You could also buy the DLC that unlocks it from the start, since you want to have as many "elite" upgrades as you can before tackling the best fleet you can get.
The best fleet you can get is all Level 60 man o' wars, which means you will need to get in a lot of trouble and raise your wanted level to its maximum to even see those ships. If you need dock space for more, just send ships to your fleet and salvage them. The more powerful they are, the better the payout will be. This fleet will survive anything the game throws at it, and you will never fail a naval mission as long as you keep them repaired.
The only downside to depending on the fleet is that it is entirely online, and you will need the Uplay Passport to access it. Thankfully it's free now.
By the end of the game, these Assassin's Creed 4 gameplay tips will see you with more money than you know what to do with.