Talking about travelling, I would mention...
-How?
-With whom?
-Where?
-Why?
The topic "language learning" contains...
-Where?
-How?
-Why?
Career choices would cover.....
-jobs (types/where)
-education (types and ways)
-extra skills (e.g. language learning, computers, driving)
Transportation would be about...
-goods (where and by what)
-people (where and by what)
When it is about holidays, ....
-types (public/personal)
-ways of spending holidays
-celebrations