Make a Bas-Relief in Plaster
A bas-relief is a raised picture, where parts of the design stand out from the background.

You will need: thin plastic tray at least 5cm deep (the sort used to pack fruit and vegetables); spoon, paper cup; two clear plastic food bags; two paper clips; scissors, sticky tape, newspaper, sand, plaster of Paris.

1. Make sure the plastic tray can hold water. If there are any holes, cover them over with sticky tape.

2. Spread an even layer of sand to a depth of 2 to 3 centimetres in the tray. Add a little water and mix with a spoon so that the sand is damp without being sloppy.

3. Press the damp sand into a firm layer with the back of the spoon.

4. Now draw a design into the damp sand. Experiment by pressing different objects into the sand to leave an imprint. Make sure you don't go too deep – you shouldn't ever reach the bottom of the tray.

5. Next, put one of the plastic bags inside the other.

6. Measure out one cupful of cold water and pour it into the inner bag.

7. Add two more cupfuls of plaster of Paris and tie the bags closed. Make sure you push out all the air before sealing the bag.

8. Gently squash and squeeze the mixture inside the bags. Be careful not to tear the bags!

9. After a few minutes, you should feel the bag begin to get hot and the mixture will feel thicker. When the mixture is about as thick as runny custard, it's time to pour it into the tray.

10. Pinch the two bags together in one corner. Snip off the corner with a pair of scissors. You have made a nozzle to let the plaster out.

11. Gently squeeze the bag and let the plaster come out into the tray. It should run into all the dips and holes in the sand.

12. Cover the sand all over with an even layer of plaster about 3cm thick. Leave it to set.

13. Throw away any plaster left in the bags. Don't pour it down the sink, or you could block the drain!

14. After about 10 minutes, the plaster should be half set. Push two paper clips into the plaster to make hooks you can hang your finished picture from.

15. After about 20 minutes, the plaster should feel hard to the touch.

16. After about 30 minutes, stand the tray on a sheet of newspaper and lift out your plaster picture using the paper-clip hooks.

Make an Artificial Fossil
You will need: the same materials as you used to make a bas-relief; sea shells, snail shells or leaves and twigs.

1. Make a tray of damp sand as before.

2. Press the leaves or shells into the damp sand so that they leave an imprint behind.

3. Mix the plaster and follow the same steps you used for a bas-relief.

Make a Pet Sculpture
Use paste and paper to make a sculpture of a favourite animal, using a similar method to Conrad.

You will need: modelling clay; wallpaper paste; paints and brushes; blunt pencil, tablespoon; bowl or bucket; newspaper; liquid soap or Vaseline.

1. Make a model of your animal in clay. This will be the armature of your sculpture.

2. In a bowl or bucket, mix 3 or 4 tablespoons of wallpaper paste with a little water.

3. Keep adding water until the mixture is about as thick as runny custard.

4. Tear the newspaper into tiny strips and add it to the paste. Stir well. The mixture should now look like thick grey porridge.

5. Rub Vaseline or liquid soap all over your clay animal.

6. Cover the model with a layer of paste and paper. Let it dry. You will need to add two more layers of paste and paper in the same way.

7. When the third layer of paste and paper is dry, turn your sculpture over. You should be able to reach the modelling clay through the base. Hollow out the inside of the model, digging out the clay with a blunt pencil.

8. Give your sculpture a coat of white paint. When this coat is dry, you can add colours.