Are there best practices for allowing orders without user account creation in osCommerce?

To allow orders without user account creation in osCommerce, you can modify the checkout process to skip the account creation step and allow users to proceed directly to entering their billing and shipping information.

// Modify the checkout process to skip account creation step
// In catalog/checkout_shipping.php, comment out the following lines:

// if (tep_session_is_registered('customer_id')) {
//   $sendto = $_SESSION['sendto'];
//   $billto = $_SESSION['billto'];
// } else {
//   $sendto = $billto = $_SESSION['customer_id'] = $_SESSION['sendto'] = $_SESSION['billto'] = $_SESSION['customer_default_address_id'] = $_SESSION['customer_first_name'] = $_SESSION['customer_country_id'] = false;
// }

// In the same file, add the following code after the commented lines:

$_SESSION['sendto'] = $_SESSION['billto'] = $_SESSION['customer_id'] = $_SESSION['customer_default_address_id'] = $_SESSION['customer_first_name'] = $_SESSION['customer_country_id'] = false;

// This will allow users to proceed with the checkout process without creating an account.