Two of my favourite ways to get the subjunctive into an oral exam or an essay:
1. "Qué yo sepa..."
This means "as far as I know" and the structure itself includes the subjunctive.
Just add your opinion in after those three words and you have yourself a simple, quick way to include the often tricky tense.
2. "No pienso que.../No creo que..."
This is another really simple structure. Just add the subjunctive after saying "I don't think that..".
E.g. No pienso que sea posible.
(I do not think it is possible.)
We use the subjunctive tense here because the statement contains some doubt.