Create a scrapy exporter on the root of your scrapy project, we suppose the name of your project is `my_project`, we can name this exporter: `my_project_csv_item_exporter.py`

```python
from scrapy.conf import settings
from scrapy.contrib.exporter import CsvItemExporter

class MyProjectCsvItemExporter(CsvItemExporter):

    def __init__(self, *args, **kwargs):
        delimiter = settings.get('CSV_DELIMITER', ',')
        kwargs['delimiter'] = delimiter

        fields_to_export = settings.get('FIELDS_TO_EXPORT', [])
        if fields_to_export :
        	kwargs['fields_to_export'] = fields_to_export

        super(MyProjectCsvItemExporter, self).__init__(*args, **kwargs)
```

In `settings.py` import this exporter and set the fields to export and the order to follow, like this:
```python
FEED_EXPORTERS = {
    'csv': 'my_project.my_project_csv_item_exporter.MyProjectCsvItemExporter',
}
```
```python
FIELDS_TO_EXPORT = [
    'id',
    'name',
    'email',
    'address'
]
```

For the CSV delimiter, you can set in `settings.py` or when you execute the spider in CLI
In `settings.py`
```python
CSV_DELIMITER = "\t" # For tab
```

OR in CLI
`scrapy crawl my_spider -o output.csv -t csv -a CSV_DELIMITER="\t"`