Quickdraw is activated in the toolbar and is used to quickly build a model from existing symbols.
Hold the mouse over a symbol to show arrows in the directions where suggestions for relations to new symbols exist. Hold the mouse over an arrow to show the suggested symbols in that direction. When you click on a symbol you will get to choose a title in the same way as when you add a symbol by clicking in the model.
The keyboard shortcut to toggle Quickdraw is Ctrl+Q. If you want different suggestions in Quickdraw, this can be configured from 2c8 Administration Tool.