When designing a SQL Server database, I like to define foreign-key (FK) relationships using database diagrams. I also like the tables in my diagrams to display the column names and their data types, for easy review and also because data-type mismatches are a common error when defining FKs and I can fix those right then and there.
Once you drop a table into a diagram, you have several choices regarding what information is shown about it. You can modify this view by right-clicking the table:
However, the default view is Column Names, and I kept getting annoyed that I had to keep changing the view to Standard in order to show column data types. Prying around, I discovered there is a way to change this default. In SSMS, go to Tools -> Options, and on the left-hand side panel navigate to Designers and then to Table and Database Designers. Once there, you may change the default table view in diagrams like this: