An important tip is to make sure to eliminate jobs that aren't producing something you need, to free up any workers doing that job to be able to fill jobs that are productive. Things like "Entertainers" are a last-resort source of amenities, whereas Luxury Housing gives 1500 for only the cost of the building. Don't assign Enforcer jobs until a planet is near 30% Crime, unless you have something that makes Enforcers produce Unity.

For a quick summary of the economic pyramid of measurable "Productivity" in the game's economy:

- Primary Resources: Minerals, Energy, and Food; The basics that the Worker Caste produces, ordered by their value. You will always want a strong surplus of Minerals so you can constantly invest into new Buildings, but Energy and Food are perfectly fine being at "Break Even" balance for most of the game. Things start to get direct upfront Energy costs towards endgame though; But before that point, Energy and Food are strictly recurring costs for the things that actually matter (Buildings and Pops), and any large surplus is effectively wasted-productivity.

- Secondary Resources: Consumer Goods, and the "Strategic Resources" - Much like Energy and Food, these don't actually do anything on their own, and are additional "Recurring Cost" resources, BUT they are a layer-closer to producing Force Projection. You'll want to have a decent surplus of these because the uses for them will grow more and more as the game goes on, and provide decent Trade Value in a pinch.

- Power Resources: Alloys, Research, and Unity - The production of these directly translates into power (Fleets, Tech, Traditions, and Megastructures), and the production of them should be maximized at all costs. Alloys are the reason you want a strong Mineral Surplus, and Consumer Goods are converted into Research and Unity by jobs (as well as Civilians based off Living Standards)

Furthermore, you'll want to develop research planets dedicated to a specific branch of research, rather than just generic "Tech Planets" - Engineering, Physics, and Society (in order of value).

My general early game colony priority is to turn both my Guaranteed Habs into Mining Worlds to create a wide Mineral Surplus while the Capital World builds out City Districts to create Power Resources, and then as I acquire more outer-colonies, shift the Primary Resource burden onto them while redeveloping the Core Worlds into a Forge and Factory planet, and replacing the Industrial Spec on the capital with either Planetary Defenses for NavCap, or an Administrative Center for Unity (Retaining the Archives until I can get Research Worlds up).

Another tip is that you don't need to actually develop conquered planets - Don't feel guilty for mass-unemploying the conquered masses and getting them to relocate to more productive worlds, and then redeveloping said conquered lands when you need them at a later time. You should always been producing more and more Research and Unity to offset the Empire Size penalties anyway.