Creating good indexes is a nuanced problem to solve. It is highly dependent on the primary use case of the data. For instance, if you have a table representing varieties of beer, you are likely to present an interface for searching by brand, or type (ipa, pilsner). Those would be good targets for indexes. However, you probably won't often search by color, so it won't be worth indexing that column.

Typically I would add any indexes initially that I know will be heavy hitters, then refine as needed based on actual use. Most databases provide tools to help identify missing indexes for common queries.