How to Create a Second Account on Any Android 

Unfortunately, as far as I know, unless you have multiple iOS devices, you cannot create additional CoC accounts on iOS. Perhaps it is possible if you factory reset your device, but it is significantly easier to do on android.The first step is to make sure your original account is connected to a google+ account, otherwise it will be lost. Please check and double check this first step so you dont lose your hard work! To make sure it is connected to a google+ click the settings button on the home (village) screen and make sure the button below "Google+ Sign-In" is green and says "Connected".

If it is red and says "Disconnected" your account is not connected and may be lost, especially if has never been connected before.

The next step is to go to your phone Settings > Apps > Clash of Clans. From there, click the "Clear Data" button. Once again, make sure your account is connected to google+ or your account may be lost.

Next, you need to add/create another google account to connect your new Clash of Clans account to. Go to your phone Settings > Accounts > Add Account > Google. Follow the steps to create a new account (or use an existing account). Once you reach the "Sync your account" page, make sure you check off "Sync App Data" (it may take a few seconds for all the options to load). I recommend unchecking everything else, unless there is anything you want to sync.

Once you have your new google account created, open the Clash of Clans app. Since you cleared the app data, it will have to download the latest content, and then the tutorial will load up. At this point, click the Google+ Sign-in button at the top right. A list of your google accounts should come up. Select the new account you just made, and run through the given steps.

There will be a few prompts for you to go through to setup and link your google+ account. Once that's done, complete the tutorial, and you can switch back and forth between by going to the in game settings page (see first image at the top of the page), disconnecting from the current google+ account (by clicking the green "connected" button) and reconnecting to your other google+ account. Once your CoC account reaches town hall 4, you will be asked to type in a confirmation message when switching between accounts.When choosing the in-game name (IGN) for your new account, please do not use the same name as your main account. This will make it confusing for other members in the clan, and also make it difficult for submitting armies, doing assignments, and anything else that requires unique names. Please also avoid any special characters or non-English letters as it also makes submissions/assignments/etc. difficult. Also, do not use the IGN "You". When you post in chat, your messages show up as sent by "You", so if there is a member in the clan with that IGN, it gets very confusing what messages are yours, and which aren't. Personally, when I log on, I scroll down the chat until I see the last message I sent, and then read up from there. Another member with the IGN "You" makes this extremely annoying, so that name has been banned from the clan.