1) Allegiance.
Cannot have 2 passports. Cannot have a 'gray' passport. Allegiance to their country, not vaguely to many. Citizenship has to be at least 4 years old to ensure migrants have fully assimilated.
2) Intelligence.
A preliminary IQ test followed by exams on history, foreign affairs, finances, economics, politics, culture. Voters should take the test every 4 years if they want to vote.
3) Experience.
An age limit of 36 years to ensure the voter has developed enough critical thinking - to not fall victim to false promises and attractive concepts. Time is a great teacher. People will learn from their own mistakes and experiences. From raising families to rebuilding themselves after bankruptcy etc.
4) Value.
Vote weight should mirror contribution to society. When someone isn't paying taxes they should not have any voting power. When someone pays a lot, provides work for others, owns land - all that should raise voting weight.
5) Community.
Proof someone is actually active in the community they are voting in.
These are my ideas about voting. I think the current systems are extremely flawed in western nations. Voting has become a popularity(deception) contest, not about ideas how to govern. A breeding ground for corruption.