I use a small cake board for sitting my figures on as if a I just work with out checking the size I tend to make them to large.
I also use a plastic place mat to work on that is dusted in icing sugar.
To make this how to I have used some old icing that needed to go in the bin so sorry about the cracks.
As I can not give you the exact sizes you need mess about with it, you do not need to use water to stick it all together until you are happy with it.
If you are colouring your own icing you will need to wear gloves other wise you will end up with coloured hands.
What you need:
ready made icing/foundant/sugar paste
Food colouring of your choice
Small rolling pin
What you do:
Dye your icing/foundant/sugar paste your desired colour. Knead until it is soft and pliable.
You need to roll out a thick sausage shape, this will be your engine bit, cut off the ends so that it is nice a tidy.
Roll out a piece of icing/foundant/sugar paste, it needs to be slightly thick, using the knife cut to size it needs to be square, this will be the roof. Once you are happy stick it to the bit where the driver would stand, make sure you only use a small amount of water
roll out a small ball, this will be your chimney, using the ball toll make a slight dent in the centre. Use some water and stick this to the engine.
To make the wheels make two large balls, these will be the back wheels, and four smaller balls, these will be the front wheels. Flatten them down using your finger then using a very small amount of water stick them onto the train.
You then need to make two really thin sausages, these will go onto the wheels, use a knife a cut them to size.
(sorry I forgot to take photo at this stage, think I was a bit distracted at this stage)
But here is a picture of one I did at an earlier date.
I find that using different colours makes the bear look better.
If you want the carriages to go with the train just make some small rectangle and stick some wheels to them.