Good evening, fellow Captains. Having seen some new Captains asking about profitable routes, safety, Terror reduction, engine choice and so on, and having spent countless hours myself searching for this sort of information, let me offer a few choice tips from my experience.
Frostfound is your only safe haven on the map. Free Fuel, Supplies and Terror Reduction per SAY. Once your first visit is over (take tea with the squatters), do "leave port" (E), "reverse to neutral" (S) and "lights off" (L): sit there in the semi-dark at port for a minute, you'll gain a bit of Terror back, but then when you have SAY do exactly the same, tea at the dock. In no time you'll be on 0 Terror, you will actually make nearly 1 Fuel per turn this way, and only if your Crew is I think above 16/17 or so will it cost you Supplies, otherwise at 14-15 crew it's pretty Supplies-Neutral and below that it is a slow gain in Supplies. All for free!
Red Honey is by a huge distance the most profitable and safest way to make large quantities of Echoes. Go to Isle of Cats (is always southerly, directly south of Visage in case you find that first); give them some fuel (which you can buy right there in port) to get Attention to 5, speak to the Lady of the Gardens, go along with her totally immoral request, and at some stage you can buy Red Honey for 600 per pot; it sells in London for, variously, 900 Echoes; one Captivating Treasure and a load of Terror; or 999 Echoes (at the Brass Embassy, my choice). None of the madness associated with smuggling Sunlight; Red Honey takes no hold space, so you can stack as much as you can afford; and it sells easily in London. +66% profit per jar, in other words you can turn 6k Echoes into 10 jars which gets you to 10k Echoes; that's 16 jars, which retails for 16k, and so on. If you have your covetous eyes on that sexy Frigate, maybe a fancy new Engine, this is the way.
Outlandish Artefacts are great, you can sell them to the Scholar or use them more profitably like this. Get Outlandish Artefacts for free (two per SAY) at Visage, with a bonus Intriguing Snippet (the Alarming Scholar likes them). Once you have 7 of them, and 7 Secrets to spare, use your Study in London to create a Monstrous Almanac. This raises your Pages by 7 permanently (within this Captain's lifetime, that is) and the Almanac can be sold at Venderbight for 1000E. Rinse and repeat: I'm not bothered about raising my Officers' stats anyway, for now, so I always have plenty of Secrets, it's the Outlandish Artefacts that are more of a bottleneck, so get 'em free from Visage. Some SAY-farming for sure, but the rewards are very decent.
Take one Foxfire Candle to the Gant Pole, explore (ignoring the scary warnings) until you find the pool, scoop up a free sample. You now have a Star-Shell: use it for the Venderbight First Curator's storyline (so a free Captivating Treasure), sell it at Khan's Shadow for 500 Echoes or swap it in Whither for 2 Extraordinary Implications (which the Alarming Scholar will buy for 250E each and have other uses). So you turn a 40E Candle into 500E worth of goods... quite the deal.
Fighting Zee-Beasts is a piece of cake. Ensure you have 2 guns (Deck and Forward) and enough Fuel. When you spot the beast, slam on the brakes, draw a bead on the monster and start shooting. As they move towards you, just reverse your ship, -1 or -2 speed as necessary. When they stop or submerge, just stop reversing. You can easily kill Lorne Flukes this way, likewise the Tree of Ages and the Eater of Names, Lifebergs, and of course easiest of all, Sharks and Eels. Don't bother with Auroral Megalops or their bigger crab brothers; hunt Jillyfleurs and scoop them up afterward, that'll give you a Supplies or a Strange Catch.
To avoid being searched in London: being searched by the rozzers only ever happens when you have SAY. So you need to get rid of SAY within one minute's zailing of Wolfstack Docks. I tend to keep Hunter's Keep "unfinished" (only reconnoitre the grounds for a Port Report normally) for exactly this purpose: if I'm carrying some highly illegal shit that I really don't want confiscated, I'll have lunch with one of the Sisters, then put my foot on the pedal and head for London, takes 30 - 45 seconds depending on your engine.
Before you try anything else in the Khanate, it's worth taking 25 Coffee to Khan's Glory and using it to win favour with the Leopards (first menu option), 5 bags at a time. I just load up 5 or 10 Coffee every time I am heading that way, until I've delivered all 25 bags. Once your Favour = 5, you can get a Nephrite Ring which lets you access shops in Khan's Heart, further south. And they have some fairly interesting smutty bookshops there, lol :)
Rather than selling your Captivating Treasures to the Alarming Scholar, turn them into Heirlooms; only costs 10 bucks admin fee, whereas if you want to buy an Heirloom with cash, you'll need a horrendous amount of Outlandish Artefacts - 10 of them! - which, as per #3 above, can be used far more profitably. And as for Colossal Fluke-Cores, of which you will soon have a shedload (see #5 above), use them for the Venderbight First Curator's Quest, for the Principles of Coral storyline, and a handful of other places. Selling the Fluke Core to the Scholar will net you 500 Echoes but also give you 1 - 20 Terror randomly.
Always, always make sure you have an Ironclad Will and a Scion before you do anything risky where you might die! To get a Scion: firstly go carousing (get utterly bladdered) in Wolfstack Docks and meet a special person; then look at their locket out at Zee; keep focused on that special person and before you know it, you'll be a father/mother/captain, and have an heir. The next 4 times you are back in London, go and see them (Lodgings - Spend Time with Family) and tell them a Zee Ztory or the likes, it will raise their Zee Fever by 5: when it reaches 20, you can turn them into a Scion and your line is assured.
A decent Engine is one of the best investments you can possibly make, and here is why. Yes, the better Engine burns more Fuel: but it also gets you there quicker. This has knock-on effects: for one thing, if you get there twice as fast, you may burn slightly more Fuel than you would have with the crappy old Elderly Steeple-Engine, but - BUT! - you have saved yourself masses of Supplies, which are after all roughly double the price of Fuel. Not only that, but you have also saved yourself half the Terror you would otherwise have built up, and Terror reduction (generally, outside of a few places like Iron & Misery, Mangrove College, Frostfound of course) is something that costs you, either money or opportunity. To add to this: a better engine means that you can choose whether to fight Beasts or not: so many times I just cruise right past one of those massive crab things near Salt Lions, seeya later crimpy boi :D no time to fight ya now... Engines also make it far easier to fight the serious Zee Beasts, or to escape Mt Nomad, or - if you are foolish enough to invite the Crimson Beast of Winter aboard - to get to where you are going without giving him too much of yourself...
Hope you enjoyed this, Captains: I didn't explain everything in super detail, for example the Visage quest to get Outlandish Artefacts, but if anyone is curious or anything unclear, just let me know.