As long as you have a dataset or two to compare, you can do just about anything with open data! One thing you can use open data for is to make informed decisions. Some examples of this could be using air quality data to decide where you want to go for a walk or looking at school district reports before moving into an area.
Other things you can do with data include creating data visualizations and apps. Data visualizations are any representation of data in a non-spreadsheet format. This can include graphs, artworks, word clouds, etc. Applications are often designed to make data easier for users to understand. One example could be taking an open dataset about public parks in the area and turning it into a map that shows the boundaries of the parks and provides directions on how to get to them when clicked on.
The following is a short list of ways in which you can use open data.
Looking into walkability scores when finding an apartment
Checking the air quality in your area
Viewing information about public parks/art in your area
Seeing who funds political campaigns
Health data can help inform patient decision-making
Finding out how schools in the area perform
See what sort of weather to expect when traveling
View crime data for your area