Begin by ensuring your Oracle environment is ready for data export. Verify that you have the necessary permissions to export data from the Oracle database. This typically requires SELECT privileges on the tables you wish to export and access to the directory for exporting data files.

Use Oracle SQLPlus to export the data. You can create a dump of the desired tables using the `spool` command in SQLPlus. For example:
```sql
SPOOL /path_to_export_dir/exported_data.csv;
SELECT FROM your_table;
SPOOL OFF;
```
This command will export the data from `your_table` into a CSV file located at the specified path.

Ensure the exported data is properly formatted and clean. Check for any inconsistencies or unwanted characters in the CSV file. You might need to use scripts or tools like `awk`, `sed`, or simple text editors to clean up the data as required.

Install and configure the AWS Command Line Interface (CLI) on the machine where the Oracle export files are located. You can install AWS CLI using package managers or download it directly from the AWS website. Then configure it using:
```bash
aws configure
```
Enter your AWS Access Key, Secret Access Key, region, and output format when prompted.

If you haven't already, create an S3 bucket to store the exported data. You can do this via the AWS Management Console or using the AWS CLI:
```bash
aws s3 mb s3://your-bucket-name
```

Use the AWS CLI to upload your cleaned and formatted CSV file to the S3 bucket. Run the following command:
```bash
aws s3 cp /path_to_export_dir/exported_data.csv s3://your-bucket-name/
```
This command will copy the file from your local directory to the specified S3 bucket.

Finally, verify that the data has been successfully uploaded to your S3 bucket. You can check this using the AWS Management Console or by listing the contents of the bucket with:
```bash
aws s3 ls s3://your-bucket-name/
```
Ensure that the size and filename match your expectations, confirming the successful data transfer.

By following these steps, you can efficiently move data from an Oracle Database to Amazon S3 without relying on third-party connectors or integrations.