There is an example here:
http://msdn.microsoft.com/en-us/library/ms996443.aspxNote that you will need to be specific about your process. You can :
1. Create a control as a composition of existing controls (a User Control)
2. Create a control by inheriting from an existing control
3. Create a control by inheriting from System.Windows.Forms.Controls
The three options require somewhat different techniques.