While personal preference is a factor the direction in which you run hardwood flooring boards is governed by visual and structural guidelines.
Changing wood floor direction.
Been there done that.
This pattern results in a hardwood floor with the appearance of a checkerboard sometimes with more complex patterns within each checkerboard square.
You can install your wood planks lengthwise into your kitchen butted against the boards running in the other direction in the adjacent room.
The traditional way to run a hardwood floor whether you are working with a nailed down or floating format is to have the planks running parallel with the longest most visible wall in the room.
Parquet hardwood floor direction this flooring pattern is the laying of wood planks in a repeated geometric pattern.
Designer karen sealy has great tips when it comes to transitioning your floors and introducing new panels.