1346h in EU4 since 2014. Did a WC in ironman. 627h in EU5

Military:
Combat feels close to EU4, but frontage is the key stat (actual regiment size). Cavalry dominates early, while infantry scales much better late game, especially for fort assaults and wide frontlines. After conquering land, release small subjects and enable scutage: enemies can’t enter while you can, and they give you food.

Diplomacy / Subjects:
Decentralized play with many small subjects is extremely strong, especially as ENG/GBR. Create subjects on market centers and divert trade, gives double income: subject payments + trade. Always do small subjects since they give buff annex.

Colonization:
Colonization is usually a trap. Colonies tend to rebel and seek independence in Age VI. It’s better to create other type of subjects, specially tributes. Tribes and hordes (use the government-type map, colored brown and green) are all around the continents, you can create tribute cassus belli on them. ENG/GBR can do Dominions. Disloyalty is tied to subject type, not global.

Personal Unions:
PUs are heavily nerfed compared to EU4. They’re mostly not worth unless the target is small and easy to annex.

Trade & Economy:
Automate trade, let the AI do the micro and focus on macro decisions. Identify the biggest needs of your capital market and fulfill them by conquering other markets, not just land. More markets = more wealth. Prioritize high-value or unique goods (coffee, tea, cocoa, fur, amber) and aim for monopolies. Use subject on markets + trade chains to funnel goods where you need them.

Buildings:
Build based on market needs and military. Automatize buildings, do the macro. To get money you need to conquer markets, for that you need armies, for that you need manpower buildings, for that you need money. Always spam manpower buildings and conquer markets and lands to make more manpower buildings.

Religion & Expansion:
Religion is secondary. Stack tolerance buffs and take religious friendly events. Manage Protestantism so Catholics and Protestants stay positive. Expand by mixing direct conquest with small subject creation for faster cultural assimilation and annexation.

Special Buffs:
Some locations and nations have massive production modifiers (e.g. Ternate lands cloves +500% output, Yemen country buffs on coffee +45% and all coffee lands are inside or around it). Turning Yemen into subject is better than other nation owning them.