Before beginning the data transfer, ensure that both Teradata and DuckDB are properly installed and accessible from your working environment. Verify that you have the necessary access credentials for Teradata and that DuckDB is operational on your system.

Use Teradata's SQL Assistant or BTEQ (Basic Teradata Query) to export the required data into a CSV format. For instance, you can run a SQL query to select the desired data and direct the output to a CSV file:
```sql
.EXPORT FILE=output.csv;
SELECT FROM your_table;
.EXPORT RESET;
```
This command will write the selected data into a `output.csv` file that you will later import into DuckDB.

If your Teradata environment is remote, transfer the generated CSV file(s) to your local machine where DuckDB is running. You can use secure copy protocols like SCP or SFTP for this task. Ensure that the CSV files are accessible and correctly formatted for DuckDB.

Open DuckDB in your preferred interface, whether it’s a command line, Python, R, or another client that supports DuckDB. Make sure you have a database file ready, or create a new one where you will import the data.

Before importing data, ensure that the table structure in DuckDB matches the data structure of your CSV file. You can create a table using a SQL command in DuckDB that mirrors the Teradata table's schema:
```sql
CREATE TABLE your_table (
column1 TYPE,
column2 TYPE,
...
);
```
Replace `TYPE` with the appropriate DuckDB data types that correspond to those used in Teradata.

Use DuckDB's built-in CSV import functionality to load the data into the newly created table. Execute the following command:
```sql
COPY your_table FROM 'path/to/output.csv' (DELIMITER ',', HEADER, AUTO_DETECT TRUE);
```
This command will read the CSV file and insert the data into the specified table, ensuring the structure matches.

After importing the data, perform checks to ensure that the data in DuckDB accurately reflects the original data from Teradata. You can run queries to count rows, compare sample entries, and check for data consistency:
```sql
SELECT COUNT() FROM your_table;
```
This step ensures that the data transfer was successful and that the data can be utilized as needed in DuckDB.

By following these steps, you can effectively move data from Teradata to DuckDB without relying on third-party connectors or integrations.