I've found in my IELTS classes that one of the difficulties the students have in expanding their answers is mostly psychological. They don't think they can expand their answers into a full 1-2 minutes, and so they give up easily.
However, if you push them to speak for the full 2 minutes, they often discover they do in fact have more things to say than they initially thought. Once this barrier is broken one time, then they usually have no trouble getting to the full 2 minutes on every subsequent practice.
For that purpose, I've been using these questions from the silly questions website.
I warn the students in advance that the questions are not IELTS type questions, and in fact are often pretty silly, but explain that being able to respond to ridiculous questions will help them to build up their confidence to respond to anything and everything.
Before class, I print out the questions and cut them up into strips, and then fold them in half so the question can't be seen.
The students are divided into teams. Each team selects 5 strips at random.
When they choose the strips from the jar, they are unable to see the question, but after they have drawn their 5 strips, they open them up to see what they have drawn.
The team chooses another team to challenge. From their 5 questions, they choose the question they like the best, and use that as the challenge question.
The challenged team selects one person to respond. (The same person can not go twice until all the teammates have had a go).
The challenged person then hears the question. They are given only 10 seconds to prepare themselves. (It's a full minute in the IELTS test, but to keep the game moving fast, and to increase the challenge level, they only get 10 seconds in this version.)
They must talk for a full minute with no pauses over 3 seconds. (The teacher keeps the time.) If they make it to 1 minute, their team gets 2 points. If they don't make it to one minute, the team that challenged them gets the 2 points.
If they talk over one minute, they get an additional point for every 15 seconds up to 2 minutes. (So a total of 3 points for 75 seconds, 4 points for 90 seconds, 5 points for 105 seconds, and 6 points for 120 seconds.)
Each team always keeps 5 challenge questions in their hand at all times, so after they've used one up, they get to draw one more for the next round.
And then it's the next team's turn to challenge.
What is your favorite way to eat a cockroach?
Why did the ghost cry on Halloween Day?
Do you enjoy swimming when it is snowing?
Why don't you want Christmas presents this year?
How did you escape from the alien spaceship?
How did you feel after watching television for 24 hours?
Would you ever wear your mother's dress to your all boys high school?
Did your parents ever have children?
Would you rather kiss a crocodile or a bear?
What is on your mouse pad?
If you were a color, what would you be? Why?
Why do people call "mouse trap" mouse trap?
Are couch potatoes good to eat?
What are the names of the eight colors of rainbows?
Why do you make your bed in the morning?
Why do you look at yourself in the mirror?
What planet are you from?
How much does your imagination weigh?
What are some of the ways can you ride a bike?
Who fell out of the apple tree?
Why do pajamas have pockets?
How long is a piece of string?
Could a husband be married to the sister of his widow?
If the number five is red, what are the colors of the other numbers?
What are the colors of the numbers 1 - 10?
What color is the number 3?
If you were trapped on an island, why were you there?
If you were given the chance to be an animal, which animal would you be?
What do you do when you are in front of the mirror?
Can we drink soda during coffee breaks?
Can we use AM Radio during the evening?
Does fire go out of the fire exit?
What are the names of the eight colors of rainbows?
How does a Boeing 747 weigh?
Do you have an Internet connection?
Is the basement downstairs?
If you were a flavor of ice cream, which one would you be and why?
What is the answer to this question?
Describe a conversation between two items in your refrigerator? (For example, what might the mayonnaise and the pickles be talking about before you open the door?)
What is a typical day in the life of your dictionary? (pet frog, walking shoes, classroom blackboard, etc.)
Would you like to be rich and beautiful or poor and ugly? Why?
When did you die?
Do you remember the doctor spanking you at birth?
Did you hang your stockings at Easter?
Did you put up a Christmas tree for your birthday?
Did you bathe in mud this morning?
Did you brush your teeth last year?
What kind of leaves do you eat for breakfast?
When were you released from jail?
What was the day after yesterday?
Why did you decide to get up this morning?
Do you ever stick your fingers in your ears? If so why?
What would life be like if you decided never to open your eyes again?
Are there days when you just enjoy having a good cry for no reason. If yes, why?
Why do people ask why?
Why do we have mirrors and what would life be like without them.
Why do your hands look the way they look?
If you could turn into an animal, which animal would you be?
Why do little children stick their tongue out at people?
Why do people pretend not to see each other sometimes?
Can you answer this question with out opening your mouth?
Would you still learn English if there was no English in the world?
Why is your breath so bad?
Were you sleeping as you drove to work this morning?
How are those anti-schizophrenic drugs that you're taking working?
How was the last Christmas you spent in jail?
How many multiple personalities do you have?