For past habits:
* Once did
* Would
* Formerly
* Previously
* In the past
* At one time
For past states:
* Was accustomed to
* Was familiar with
* Was in the habit of
* Had a habit of
For past objects:
* Former
* Ex- (as in "ex-boyfriend")
* Old
* Previous
For introducing an example:
* For instance
* For example
* Such as
* Including
For expressing something that was common:
* Commonly
* Usually
* Typically
* Often
The best synonym to use will depend on the specific meaning you want to convey.