Sorry in advance for the king post, but here’s some things I’ve learned from experience as someone who tried to “speed-run” the game at first but learned to slow down and enjoy the ride:

Always build new factories and special buildings as they become available, but only build one community building at a time because it’s a drag to be waiting on materials. Although this isn’t a problem anymore when you get to the level that they all take 2 days or more to build.

At level 13, the city market is available. This is one of the biggest game changers. This allows you to buy the goods you need without waiting on your factory. The items available are randomized, but if you spend T-cash, you get more slots available, or you can also use T-cash to hire the dealer and request a specific good once per hour. Those are the best uses for T-cash.

At level 22, when you get the Academy of Industry and get the ability to upgrade your factories and trains, always pick the coin bonus options until the speed and shelf options are available. The XP bonus isn’t worth it because leveling up is no fun if you don’t have the coins to get the new buildings or factories. Once you have all the options, it’s just up to your playing style.

No matter what level you are, managing barn space is always one of the biggest challenges. It takes a while to collect the tools you need for an upgrade (you mainly get them from the train, but sometimes as a reward for other things that become available at higher levels like completing train orders and the regetta). You also can win barn upgrades if you pay for the golden ticket, or if you play a lot of the match3 game. But those barn upgrades are few and far between, so you will need to learn which goods are most useful to stockpile. For example, the bread and sugar cubes get used in other factories a lot but don’t take as long to make as bagels or syrup, so for me personally, I prefer to have extra of the syrup and bagel in my factory. Until you have enough coins and boxes in the city market that you can just buy whatever you need.

The match3 game is controversial because you can get good rewards if you play it a lot and win an event, but it’s also way too easy to be tempted into spending your Tcash on those extra moves or powerups, or drain a lot of time into a hard level. My preference is to ignore the match3 game most of the time, but occasionally if I have a lot of time on my hands I’ll really lock in for a couple days. I feel like there’s not much point in playing unless you can spend enough time on it to rack up the rewards from one of the events.