Set up:
Study your cards and determine if they complement a geographical area of the board. If so, this can be a good place to set up most or all of your ships. Once ships are deployed to the Atlantic, or the Gulf, it is expensive to reposition them. Having all your ships either on Confederate ports, or on foreign ports allows you to concentrate on specific commodities at a time. This has two benefits; 1. It easier to get the war good delivery action bonus. 2. A strong purchase of any specific commodity will ensure you a higher profit than the following players since you will both reduce the availability and drive the price down with your delivery.
Recognize that if you set ships up in Confederate ports, while you can make enormous profits on cotton, you will risk immediate and disastrous ship captures.
Place your ships with their speed rating in mind, so they can actually reach where you would like them to go in one movement phase.
Actions:
A typical first move is to; 1. Load 2. Move 3. Unload 4. Bid on ship - if you delivered valuable commodities, as other players will not have the capitol you have after your unload payoff. This ploy, however, will often leave you in last place in turn order as you might have the highest cargo capacity. Thus, this 4th action could be another Load Action depleting the local supply for ensuing players.
This game is mostly about avoiding expensive risks. When risking ships with loads, it is always better to risk cotton or war goods as your cargo, since the monetary loss for this cargo is insignificant. Try to work your actions so that you are not loaded with expensive tobacco while in a lightly defended Confederate port at the end of your turn as this could be disastrous if the port is assaulted.
It can be beneficial to even use a Move Action immediately after an Unload Action to return your ships for the more valuable cargo, or to bring them safely out of the Confederate ports before that turn's blockade is drawn. It is entirely possible to avoid all blockades (except the High Seas Squadron), during the whole game by using this ploy, but the opposition may make more money by actually carrying cargo on every run.
When using a Rail Action, it can be beneficial for you and detrimental to opponents, to remove commodities from other ports as well as inland.
Card Play:
This is something you try to avoid altogether, but when necessity arises, can be a big help. Whenever playing a card, attempt to ensure that its play benefits other players as little as possible, and yourself as much as possible. Cards that directly help your own ships by providing them bonuses on rolls do this most obviously, but also have the least long-term effect on keeping ports you use open. It can be a good idea to focus many of your ships together and focus your attempts on keeping a port open that you get more use of than other players. Another great example involves moving later in turn order and playing a Rebel Raider to remove the High Seas Squadron after it has successfully restricted other players. Building up port defenses using the Port Defense Fund is always a good idea, even if the use is not very beneficial for you, as it denies other players the ability to use it more effectively. You may even be able to use the PDF to assist another player in exchange for a card play or trade, or some other benefit for you. Cards like Insurance, Pilots and Captains can often be good to play early in the game to receive their benefits for the duration. Trading cards can be important, especially as you might have some cards that while not very helpful to you, can be quite helpful for another player.
Risk Management and Turn Order:
Try to avoid risks as much as possible, especially if you are ahead. The onus is on players falling behind to take risks to catch up to the frontrunners. Although the odds of rolling double 8's are low, it does happen on occasion, so it is beneficial to make as many completely safe runs as possible, either by eliminating blockades entirely or increasing your odds to where even rolling double 8's allows escape.
Losing a ship isn't always the end of the world. Remember that turn order is based on fleet capacity, so be ready to alter your strategy to take advantage of an earlier turn order position if you suffer casualties. Players moving earlier can purchase commodities from ports where opponents have ships (either in the port itself or by railing to other ports). Players moving earlier also, besides getting cheaper and easier access to commodities, receive better rates for delivery.
Negotiation:
If you have any cards that could affect the High Seas Squadron, it can be crucial to save them until you or another player needs them. This can be quite useful for a coercive agreement. Be willing to trade cards at any time as even a trading for a worthless card can cause another player to use the Play Card action, depriving him of another potentially more profitable action.
End Game:
On the last turn there is little reason to bring in war goods. Try to be in a position at the end of 1864 to gain the maximum monetary cargo available. Keep in mind that the loss of a valuable ship is a loss of net worth at end game. Sometimes it can be better to sit it out at port, than risk the ship.
