SPF and DKIM are necessities in order to improve your email reputation and deliverability.
But now it is not enough. DMARC has become in new standard for Emails.
To generate a DMARC, just visit the below link :
https://mxtoolbox.com/DMARCRecordGenerator.aspx
Once your DMARC record is generated, go to your DNS manager and create a TXT with Host/Name: _DMARC