Ok, so i will be showing you how to Branch mine. Tree mining is a way of mining a 2x high tunnel while for every other top block, you mine as far as you can so you can find more minerals as shown. Now that you have that, you must keep doing this until you find minerals. Note though, it is better to mine at the last layer at bedrock, and bring alot of torches and food and equipment. You are then likely to find mobs when you go. You also must be at either a unowned region, or a region you have permission in or own. You must also be a settler or higher.
Sorry lol, i have always seen in videos and on sights it bieng called tree mining. I will see if i can edit it since this is my 5th post