Enable two-factor authentication (2FA) in your DMarket account settings.
Use strong passwords for your DMarket and email accounts and reset them regularly. You can set up a password manager to make this easier.
Never disclose your account password to anyone.
Always verify website authenticity. Check the connection type (HTTPS or HTTP) and URL. It should be https://dmarket.com/. Never enter your DMarket account data on other websites.