Performance Optmization with .NET

I have a web service, so the handler is called multiple times concurrently all the time.

Inside I create SqlConnection and SqlCommand. I have to execute about 7 different commands. Different commands require various parameters, so I just add them once:

command.Parameters.Add(new SqlParameter("@UserID", userID));
command.Parameters.Add(new SqlParameter("@AppID", appID));
command.Parameters.Add(new SqlParameter("@SID", SIDInt));
command.Parameters.Add(new SqlParameter("@Day", timestamp.Date));
command.Parameters.Add(new SqlParameter("@TS", timestamp));