Changing to a new Android Phone
Transitioning to a new cell phone has gotten a lot easier since the days when I wrote all the numbers I had stored in my Nokia's memory on a sheet of paper only to enter them in again by hand on the new phone. However, there are still some things you should consider when you get a new Android phone.
To set up the new phone, charge it, turn on and connect it to wifi. There's no reason to switch over the SIM card until you're ready to go. It's easier to set up the new one while you still have the old one available to reference and retrieve any data you may need.
The first things you should make sure get transferred are any two-factor authentication keys that may be authorized on your old phone. I use two factor authentication on any website that provides the feature (Google, Dropbox, Amazon AWS, Coinbase, and Github). Open up your Google Authenticator app to make sure you get all of them. The transfer usually has to be done within the security settings section on the website of the company and not on your phone. It's a good idea to make your new phone the primary for all of your two-factor authentication before getting rid of your old phone.
It is important to get any data you care about onto your new phone. Some apps have a built in way to export settings like the Gentle Alarm App and DogCatcher podcast app. Some have sign ups for cloud services that you can opt into like Key Ring. I automatically get any pictures or videos put in my Dropbox via the awesome automatic Camera uploads feature. I also have all of my music and movies backed up in Dropbox, but if you don't you'll want to copy them to your new phone. Some games have dedicated apps that will back up and restore your progress for you. If you can't bear the thought of going through Angry Birds and pain stakingly regaining all of those perfect three-star completions, try the backup app.
One of the best things about the age of cloud services and smartphones is that for most things you don't have to worry about transferring anything to your new phone. Gmail, Facebook, Twitter, Google Calendar, Google contacts and many others have all of your data in the cloud so there's nothing to transfer to your new phone. You simply have to sign into the service on your new phone and you're ready to go. The Google Play Store also knows which apps, music, and movies you've purchased so you can get those right away on your new phone. After doing all of this I used my new phone for a few days just to make sure I wasn't missing anything. The next important step is to sell your old phone.
Used smartphones are worth a surprising amount of money on eBay. It is definitely worth your while to get your phone sold. This also lessens the total cost of owning a phone, and can be used as justification to get a new phone more quickly. The first thing to do is to get all of your personal information off of the phone. Android has a built in reset option. This is reached by pulling down with two fingers from the top and hitting the settings button. From there scroll down and select the "Backup & reset" option. Under the "Personal Data" heading there is a "Factory data reset" option. This gives you a gentle reminder of the things you will lose, but since you've been following this guide, you can safely ignore this and tap the "Reset phone" button at the bottom. It warns you again, but just go for it, hit "Erase everything". You'll get a nice animation of the Android mascot spinning something in his stomach, which in this case I guess means losing his mind. At this point your data has been erased, but not overwritten. In this state it would be pretty easy to recover your data since it hasn't been overwritten. To take care of this I booted the wiped phone and filled up all of it's empty space with some non-personal data (i.e. movies, music, or anything really that doesn't have personal information on you or your family). After doing this, it will be much harder, if not not impossible to get at all of the personal data you had stored on your phone. If you're more paranoid than me, I suppose you could do that more than once, but I don't think it really gains you anything. Enjoy your new phone. Be glad you're not punching in saved numbers by hand.