This is an extremely simple, zero preparation and fun idea for creating conversation lessons with high intermediate or advanced level classes. You take a simple picture featuring one or more people and use it as the basis for some imaginative storytelling. Here is an example with suggested questions - I'll write them in English so you could adapt them for any language.
What's her name?
What's his name?
Where are they? What country? What town?
What's their relationship?
Did they meet recently?
Are they work colleagues?
How old are they?
What are they eating?
What are they talking about?
What is she like as a person? What's he like?
What are their interests?
Why do they look so happy?
How did they meet? When? Long ago?
If they are married, have they been married before?
What were they doing before they met at the restaurant?
What are they going to do next?
What do they do for a living?
What do they think of their jobs?
Have they always done that?
What did they used to do?
Do they have any guilty secrets from their past?
Have they been on holiday together? Where? When?
Now, how the conversation develops depends on just how imaginative your students are. You would do well to tell the students at the outset to be as daring as possible. They may take you in some interesting directions; or you may need to prompt them to use their imaginations a bit more by suggesting some more outrageous ideas, e.g. he has two wives, she is a spy, he is an ex convict, they are having an affair, and so on.
I would probably do this a teacher-led task, but with some classes you hand out a list of suggested questions and get the students to work in pairs or small groups. This would lead to a variety of stories which can be compared later on.
When you do this type of activity students come up with different scenarios. This can generate further debate. If you are leading the lesson, you may have to lead them along what seems like the most fruitful linguistic and creative path.
It's easy to encourage the use of different time frames - past, present and future - and to go on from speaking to writing or more listening. For example, you could make up your own back story to the couple, describe it in TL to the class, whilst they take notes, then feed back the account to a partner or the whole class.
How about getting them to write an imagined dialogue between the couple, once their story is established? Or how about getting the students to find their own picture and build an imaginative story around it, either spoken, written or both.
All in all, you can end up with a low prep lesson which generates bags of spontaneous TL input and output along with some creative fun. It's the kind of lesson which makes a change from grammar bashing or another text on that same old topic!