If I look at a map from the famous Cartographer Willem Blaeu, I can notice the following.

Ocean labels - Small caps starting with a capital character. Wide tracking between characters.
Continent labels - Small caps, sometimes starting with capital character, sometimes without.
Country labels - Normal characters, Bold, starting with a capital character.
City - Small characters, italic, starting with a capital character.

Mountain ranges - Small characters, italic, starting with a capital character
Lakes - ?
Rivers - ?
Forests - ?

Are there any rules for labeling?
At what side of a city icon should I add the labels, above or below?
What side do I tilt my text when a mountain or a river is placed vertically?

Would love to hear you guys opinion about this.