Don't make your country overpowered and invade everyone. Also focus on economy.
You can only create an alliance if someone wants to join before you make it. Also make peacekeeping alliances, economic alliances, and not just military.
You can NOT create a country in the middle of the ocean. Basically you can't just make your own island or (You get the idea)
Remember the geography in where you are invading/passing through, like mountains or deserts. You can only do rebellions in countries that no body is being as there main country.
Just ways to make the game more fun :D
Alliance with countries for good reasons.
Change your name when you change ideologies, like if you turn communist, change your name from ggg to The Peoples Republic of ggg. Not everything has to be historically accurate.
Somalia (pirates optional)