It's nice to show cool gradient color as a
background color of the form in c#.net desktop
application.you can set different colors.

command objects use parameters for passing values
to sql statements for type cheking,validation,guarding
against SQL injection attacks,etc.so its a good practice
to use command parameters to sql statements.

you can put application specific settings in the
appSettings section of your app.config file in your
c# windows form application.you can access,edit,update
those settings.I show you how -

if you want to prevent running multiple instance
of the same c# application then check the
following lines.It's sometime necessary to prevent
running multiple instances of the same application.

namespaces is a old concept in c# programming.both
java and c# uses this concept.a namespace is act like
a 'wrapper' around one or many elements which gives
them uniqueness.