The most important thing long term.Edit
If you get bankrupt at high level and you can't manage to sell items you make with fresh noob workers right away, you have lost the game and can't get back in it aside from abdicating (which won't give you your 100 starting tokens back).
The most basic solution to this is to play it safe. Always have a few days operational costs worth of gold on you so you can stay alive after a slump or a streak of bad luck. At higher levels, you will experience several days of loss and then a day of huge profit. Knowing how much you can earn and how much can can expect to lose in a worst-case scenario is key. If unsure, play it safe.
Players who invest heavily in the silver-tongued skill and Suggestion-augmenting improvements can help with producing sales when they have very few items after bankruptcy (again, not a problem if you play it safe and just don't go bankrupt in the first place). It has a practical side in normal gameplay though, when your workers are all very high level so you can make highly profitable long to make items and always sell 'em regardless of what people actually want (provided they actually know how to use it). Silver-tongued skillpoints synergizes well with sorceress, who produces items that can be bought by everyone.
Mercantile also helps financially by directly increasing the money earnt through sales and decreasing money lost through purchases.
However, long-term game play leads to a stage where experience, getting the materials to make rare items and a great deal of income all stems from quests. That is why a lot of players recommend investing many skill points in the Adventurer skill.
-The skills that matter most when hiring a worker is the highest (normally near 15 to 19). Hire accordingly unless you want to have a specific worker type. If you can't be bothered to remember what customers can be suggested successfully, get a sorceress: all customers can be suggested potions and other consumable items.
-Keep at least 200 gold as the absolute no-matter-what minimum so you don't lose your inventory and workers at the end of the day. 2000 is much, much more comfortable and 20,000 means you can always buy items and recipes off customers.
-Don't train your workers yet! Keep them producing really basic, quick-to-make stuff until you have 10k profits!
-If you research stuff, do it with one worker at a time only. This prevents the situation where your store inventory is going near empty and you lose everything, or get the recipes and lose everything. It's best to stock up on known recipes based on throughput before having a worker perform research (i.e., if you sell six Alert Dust on a good day, then stock twelve during a two-day research).
-If a quest shows up (the first one being the stolen bag of 4 leaf clover) do it as soon as possible. Basically you wait for a questing-type adventurer to show up, switch him on that quest. The first quest brings 5000 gold coins plus adventurer loot!
-GUILDS: "There are no guild fee's anymore please forget this section" Don't join any guilds unless you have 1000 improvement points to trade and need improvement points for an improvement that you bought. (improvement points are useless to you, unless traded for someone else's improvement points while in a guild or used towards a quest while not in a guild). Don't stay in the guild beyond that, and don't be afraid to create a guild just for one game day, for it since on the first game day there is no guild fees.
-If you're rich enough to train workers, have their main skill become a multiple of 25. That way, they can make the basic items of their trade in 1 hour. If your worker is a few points short, it might still work out as one hour - the game is a little forgiving for that. (according to forums, you need a multiple of 23 skill points to get basic items in an hour, but this is most likely because of Leadership skill. It may be that one point in leadership equates to one point of worker skill boost that is not shown)
-If you don't have what the customer wants, try suggesting (in order): an item of the same type usable by his class, a consumable (every class can use it), or, if you don't know what the class can use, try selling something that you just really want to sell. You have a smaller chance of success if the price are widely different from what the customer wanted, and the game notifies you of the % chance of success only after you try it...Typically, if you offer the item earlier in the tier of a type (i.e., customer wants Suple Dust but you offer Elemental Dust), the likelihood of the customer accepting the offer is about 50%, adjusted for price differences.
-As a general rule, it is always best to sell an lower tier item to a customer if you have an excess of it and none of what they're asking, regardless of how far below market value it is. Customers are the biggest resource in this game, so it is better to sell an item for 50% of it's value than having only a 20% chance to haggle it for 75% of it's value. Exceptions to this rule are if you either cannot make a particular item (such as a slicer in early games) due to lack of research or lack of the right worker. You may want to hold on to a more rare item just in case it is requested for a quest.
-Keep your tokens! Thugs ops and special recipes and rare ingredients to make stuff will come from leveling yourself up and from your customers if you are patient! The only things certain to not be available to the patient player are the shop stats change (50 tokens) and the capacity to have more days in reserve.
After some more weeksEdit
-It is time to form a permanent guild.
Since guild fees increase with the number of players in it, it is best to find a guild with a total of 2 workshops per workshop types. That's either 4 new players with 2 workshops each, or 2 veteran players with all 4 workshop types. Anything else costs more gold for what it does and thug protection is only worthwhile much, much, much higher levels where guild fees are nearly irrelevant pocket change. There are no more guild fees, you can join and stay in clans without pay.
-Train your workers to skill multiples of 25 (23?) to get the most basic items done in one hour instead of 2. Spam really basic items until you have 100+ since you'll never produce 'em again at the most efficient time/cost possible because eventually you'll have 50 skill on your (now expensive) worker and won't want to produce extremely low level stuff again because it's just inefficient.
-If your workers are overtrained for the customer count you have, you need to suggest something else (more expensive stuff) to most customer most of the time at some point - better get those improvements that bring more customers in rather than make a 3rd workshop that would only compound the problem of not enough customers!
Customers will usually only wait one hour if you tell them to wait (possibly one more for every improvement that increases customer patience), so don't expect them to hang around to finish that Gladius if it will take three hours!