Scratch org Config Examples - For More: https://developer.salesforce.com/docs/atlas.en-us.sfdx_dev.meta/sfdx_dev/sfdx_dev_scratch_orgs_def_file_config_values.htm

gistfile1.txt

// example of how to configure SecuritySettings in your scratch org.
{
  "orgName": "Acme",
  "edition": "Enterprise",
  "features": [],
  "settings": {
       "mobileSettings": {
          "enableS1EncryptedStoragePref2": true
       },
      "securitySettings": {
          "sessionSettings":{
             "sessionTimeout": "TwelveHours"
          }  
      }
  }
}

gistfile2.txt

{
  "orgName": "Acme",
  "edition": "Enterprise",
  "features": ["Communities", "ServiceCloud", "Chatbot"],
  "settings": {
      "communitiesSettings": {
          "enableNetworksEnabled": true
      },
      "lightningExperienceSettings": {
          "enableS1DesktopEnabled": true
      },
      "mobileSettings": {
          "enableS1EncryptedStoragePref2": true
      },
      "omniChannelSettings": {
          "enableOmniChannel": true
      },
      "caseSettings": {
          "systemUserEmail": "support@acme.com"
      }
  }
}

gistfile3.txt

// Create a Scratch Org for a Specific Release
{
   "orgName": "Dreamhouse",
   "edition": "Developer",
   "release": "Preview",
   "settings": {      
      "mobileSettings": {
          "enableS1EncryptedStoragePref2": true
      }
   }
}

// sfdx force:org:create -f config/project-scratch-def.json -a PreviewOrg -v DevHub release=Preview

gistfile4.txt

sfdx force:user:password:generate --targetusername <username>

project-scratch-def1.json

{
  "orgName": "Demo company",
  "edition": "Developer",
  "features": ["EnableSetPasswordInApi","PersonAccounts"],
  "settings": {
    "lightningExperienceSettings": {
      "enableS1DesktopEnabled": true
    },
    "mobileSettings": {
      "enableS1EncryptedStoragePref2": false
    }
  }
}

project-scratch-def2.json

{
  "orgName": "FSC Scratch",
  "edition": "Partner Developer",
  "namespace":"NEDNameSpace",
  "features": ["Communities",
    "ContactsToMultipleAccounts",
    "PersonAccounts",
    "IndustriesActionPlan",
    "DocumentChecklist",
    "FinancialServicesUser:10",
    "FinancialServicesCommunityUser:10",
    "FlowSites"],
  "settings": {
    "lightningExperienceSettings": {
      "enableS1DesktopEnabled": true
    },
    "securitySettings": {
      "passwordPolicies": {}
    },
    "mobileSettings": {
      "enableS1EncryptedStoragePref2": false
    },
    "communitiesSettings": {
        "enableNetworksEnabled": true
    }
  },
  "objectSettings": {
    "account": {
       "defaultRecordType": "PersonAccount"
    }
 }
}