Action Details
Requirements and how-to articles for TikTok's action:

Create a TikTok account using either an email address, phone number or existing social media account.

You need this to get it done:

iOS or Android Mobile Device
An iOS or Android device is required in order to be able to use the official TikTok app to create an account.
Email Address
You can use an email address to sign up, which is where your confirmation code will be sent.
Phone Number
You can use a phone number to sign up, which is where your confirmation code will be sent via SMS.
Social Media Account
You can sign up using a Facebook, Google, Twitter or Apple account. If you sign up using an existing social media account, your name and profile picture will be carried over to TikTok. You can add your YouTube channel and/or Instagram ID to your public profile.
Choose a unique username. You can change your username once every 30 days.
Enter the name you would like to be known by on TikTok (unlike your username, this does not have to be unique.)
Profile Description
Write a short bio for your profile.
Profile Photo
Either choose a photo from your gallery/library or take a new one.
Profile Video
Either choose a video from your gallery/library or take a new one.
Date of Birth
Your date of birth will not be shown publicly and is just to confirm that you are over the age of 13 (if you sign up using another social media account, this step is not required.)
Requirements missing or found errors? Report

How-To Articles
A list of useful links for you:

TikTok Support - Create a Tik Tok Account
Official information about creating an account on TikTok.
Wired - How to Use TikTok: Tips for New Users
Beginner's guide to TikTok, includes brief guide for creating a new account.
Fanbytes - Beginner's TikTok Marketing For Brands
Information about how to effectively market your brand using TikTok.
Link missing here or found errors? Improve How-Tos