Here are some different ways of expressing an opinion :

– I feel strongly about …
– From a … point of view
– Someone should do something about it. (To make a change)
– To share an opinion.
– In my opinion…
– As far as I’m concerned …

Asking for an opinion :

– How do you feel about … ?
– What are your thoughts on … ?
– What do you think about … ?
– What’s you opinion ?

Agreeing :

– I agree.
– That’s true.
– I share your opinion.

Disagreeing :

– I disagree.
– That’s not true.
– I’m against …