For absolutists:
- model your country after North Korea (censorship, no freedom of speech, conscription, political prisoners, aggressive isolationist foreign policy...)
- Take into consideration the far reaching effects of your desisions, even if you have, as king, utmost power.
- re-open and subsidize factories
- research military, cultural monuments
- raise taxes to cover expenses (wars, etc.)
- preserve religion
- maintain serfdom
- centralize authority (take nobles' power away, invest in government administration)
- maintain military strength
- If you feel obligated to.... attack weaker countries for control, show them who's boss
- consolidate power-annex vassels and the like, and attempt to centralize power
For constitutional monarchies:
- Depending on the restrictions of the constitution, raise taxes so that the people can still afford their daily needs. (Could do the same about ruling like an absolutist ^, exccept do not make large changes that would take away the purpose of a constitution)
- Make your desisions based around constitutional limitations.
For republics:
- Begin to see what your country consists of (people that are conservative, liberal, etc...)
- Listen to what the people want.
- Eliminate tariff barriers because it would encourage trade.
- Having a fair taxing envoirnment (everyone gets taxed the same amount, regardless of social class).
General:
- Ally with the countries who will grow in the near future
- Think about the consequences and profits before starting a war
- Help out your colonies (if you have any) because they will help out in the long run
- Make sure choices are the reasonable and/or helpful to your own country
- Competing with other nations has its risks and rewards.
- Before making any big desisions, think about the effects.
- Trade exports for more money.