Best practice? open and close multi connections, or one large open connection for ado.net

I am using ADO.Net for some database connectivity and I was just hoping I was doing it the right way. I am opening and closing multiple connections for each stored procedure. Or should I be wrapping this up in just one open connection (less resource on the database maybe?) thanks, and if there is anything odd or something I could be doing better let me know thanks!

Example: this but I have like 6 of them...

using (SqlConnection conn = new SqlConnection(ConnectionString))
{
    SqlCommand cmd = new SqlCommand("spSelectAllTrip", conn);
    cmd.CommandType = CommandType.StoredProcedure;
    conn.Open();
    ddlTripTypeA.DataSource = cmd.ExecuteReader();
    ddlTripTypeA.DataTextField = "TripType";
    ddlTripTypeA.DataValueField = "TripTypeAID";
    ddlTripTypeA.DataBind();
}
using (SqlConnection conn = new SqlConnection(ConnectionString))
{
    SqlCommand cmd = new SqlCommand("spSelectAllTripB", conn);
    cmd.CommandType = CommandType.StoredProcedure;
    conn.Open();
    ddlTripTypeB.DataSource = cmd.ExecuteReader();
    ddlTripTypeB.DataTextField = "TripType";
    ddlTripTypeB.DataValueField = "TripTypeBID";
    ddlTripTypeB.DataBind();
}