How do you make homemade chocolate icing?

icing sugar in its easiest form is just icing sugar and water (or milk). just start with 1/2 cup of icing sugar and add water until you get the consistency you want. once you get the consistency down, mix in some vanilla to give it some flavor. start with 1 tsp of vanilla...go from there. if you need more then 1/2 cup of icing, just start adding more icing sugar and water...keep mixing...don't forget to add more vanilla as well. this is just a simple icing. if you find it has too much of an icing flavor, try a tbsp of butter as well. it's all hit and miss with icing. for more complex, consult the internet or cookbooks. i have made mocha icing (yum), butter icing, cream cheese, etc.