Execution Flow

Obtain domain name and certificate to spoof legitimate site: This optional step can be used to help the attacker impersonate the legitimate site more convincingly. The attacker can use homograph attacks to convince users that they are using the legitimate website. Note that this step is not required for phishing attacks, and many phishing attacks simply supply URLs containing an IP address and no SSL certificate.

Techniques
Optionally obtain a domain name that visually looks similar to the legitimate site's domain name. An example is www.paypaI.com vs. www.paypal.com (the first one contains a capital i, instead of a lower case L)
Optionally obtain a legitimate SSL certificate for the new domain name.

Explore legitimate website and create duplicate: An attacker creates a website (optionally at a URL that looks similar to the original URL) that closely resembles the website that they are trying to impersonate. That website will typically have a login form for the victim to put in their authentication credentials. There can be different variations on a theme here.

Techniques
Use spidering software to get copy of web pages on legitimate site.
Manually save copies of required web pages from legitimate site.
Create new web pages that have the legitimate site's look and feel, but contain completely new content.

Convince user to enter sensitive information on attacker's site.: An attacker sends an e-mail to the victim that has some sort of a call to action to get the user to click on the link included in the e-mail (which takes the victim to attacker's website) and log in. The key is to get the victim to believe that the e-mail is coming from a legitimate entity with which the victim does business and that the website pointed to by the URL in the e-mail is the legitimate website. A call to action will usually need to sound legitimate and urgent enough to prompt action from the user.

Techniques
Send the user a message from a spoofed legitimate-looking e-mail address that asks the user to click on the included link.
Place phishing link in post to online forum.

Use stolen credentials to log into legitimate site: Once the attacker captures some sensitive information through phishing (login credentials, credit card information, etc.) the attacker can leverage this information. For instance, the attacker can use the victim's login credentials to log into their bank account and transfer money to an account of their choice.

Techniques
Log in to the legitimate site using another user's supplied credentials

Phishing