4 Choices of Ships, 2 Docks and 1 Premium Dock.
Strategy 1: 2 Icebergs (Provides good balance of coins and books for research), allows for instantaneous upgrades after each Great Library upgrade.
Strategy 2: 2 Glimmering Dales (Suggest to do this once your valley reaches Valley level 6 when the main focus is on Guilds). Provides abundance of coins for players to focus and upgrade their village while key infrastructures like Brick workshop and Sawmill are being researched. Guilds will require bricks and planks at levels 4-6 respectively. More information can be found at the respective pages.
Villager skill upgrades