•You should speak to him about it.
•You should see a doctor.
•You should ask a lawyer.
We use 'should' to give an opinion or a recommendation.
•We should invest more in China.
•They should do something about this terrible train service.
•He should resign.
'Should' expresses a personal opinion and is much weaker and more personal than 'must' or 'have to'. It is often introduced by ' I think'.
•I think they should replace him.
•I don't think they should keep the contract.
•Do you think I should tell her?