It's a good idea to use a class say gateway where all
database access codes will be written.in this gateway class
you will implement db connection as follows -

first create another class -

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.

master pages creates a common look in your application.
if we think about the header and footer in our pages,we
create these header and footer in every aspx pages.this
method has disadvantages.if there were any custom page
which dynamically adds header and footer then would be
good.

The great control in the asp.net ajax is the update
panel control.it can be added to almost every
asp.net page almost magically.this control when
used with a ScriptManager permits a programmer to
use partial rendering(a technique by which many
sections of page updated partially without reloading
the entire page).

all asp.net handlers implement the interface of IHttpHandler located
in the namespace of System.Web.ISAPI(Internet server application
programming interface) extensions are somehow analogous to Handlers.