You can combine values from multiple fields or build a conditional value using a Marketo Formula field.
Go to Admin and click Field Management.
Click New Custom Field.
Select Formula for the Type.
Enter a Name for your field then click Create.
Find and select your formula field then click Edit Rules.
Add two choices and define them like the screenshot below.
Learn more about tokens for flow steps.
Now you can add the formula field as a token in an email.
Formula fields can be used in landing pages, emails and smart list columns (they are not exported). Emails with formula fields can not be sent using a batch campaign. Please use an email script token in this scenario.
Good work! Now you have a smart field that knows what salutation to include based on gender. Have fun with this and get creative.