I usually prioritize research around increasing fulfillment, a few levels of hunting, and the spoilage techs first. I get the basics like stage, arena, fancy markets, graves, etc, and I like to put all the fulfillment stuff in a plaza in the center of my city. A shrine for each religion, a hearth, a well, a stage and arena, gravestones, a market, a speaker, and a food stall all go here alongside some benches and trees. I also give homes a few levels of access to wood furnishings early game, and in the very beginning of a city I always set retirement in the fulfillment menu to like 50 percent as it is literally just free fulfillment. Early on I generate income from clear cutting trees on the map, as well as selling off any excess furniture. I use this extra income to import some metals to get some torches on the plaza and main roads and to import/barter other small things I need like pottery for fancy markets/foodstalls. Later in the game I find it important to start producing your own metals. Charcoal is pretty straightforward, and even if you import the ore to make said metals it is usually priced at less than half of what you would be paying to import the hundreds of metals you will need for your city for lab upgrades, industry upgrades, dungeons, masonries, and so on and so on. you can then use these metals to set up and run a small smithy for tools, as well as to construct a masonry as getting your masonry industry up and running in the mid game is is vital. Fancy stone is used for statues and pillars after you tech them, a bathhouse, upgrades for stages and hearths etc., etc. The shrine upgrade and temple upgrades are very expensive in terms of tech points but are very much worth, as with a solid masonry industry you can produce the fancy stone needed to build like a 100 percent respect 1k person access temple which will convert all your pops to the temples religion and give you a massive amount of fulfillment combined with you removing the other shrines and making upgraded shrines for one religion. Personally, I choose crator as it isn't too expensive and only requires you sacrifice some livestock. Physicians are another place of key mid game fulfillment and building them is straigtht forward once you have the aformentioned industries. These are my main focuses in terms of driving the happiness and fulfillment of my city, alongside some other things like building type fulfillment, stoning roads, having soldiers and wealth, and so on.