Use made of to talk about the material of an object - wood, plastic, glass, crystal, etc.
- which has not gone through very much processing. You can still see the original material:
This table is made of wood.
The window is made of glass.
This shirt is made of cotton.
Use made from to talk about one object that came from another, different object:
This purse is made from recycled plastic bags.
Cheese is made from milk.
Wine is made from grapes.
In each of these cases, you can't see the original materials anymore (plastic bags, milk, or grapes); they have been transformed into something completely new.