Dont worry i will enjoy the challenge.Whay colour or colours?Maybe do a rainbow one,then keep everyone happy.Open to suggestions.
I have made one before but just using a medium plastic ball.wrapping wool round.Then you make long strands of wool,cover over as if making a wig but cover all ball.Tie up so it looks as if in middle of ball.You then use the long strands to make eight plaits.Check sufficient strands to balance out.Tie with coloured baby ribbon.Sew on felt eyes and mouth.
you can also make small ones.Or make assorted spiders for halloweenusing the same method. Happy plaiting.lol