Step 1: Get picking
Load GarageBand from your Dock or Applications folder and you will see this window. Click on New Project on the left, then Loops and click Choose.
Step 2: Name, time, go
You now have to pick a name for your track and a location to save it. You can also change the tempo, time signature and key. Leave alone if you are unsure.
Step 3: So empty
You will now see a very empty interface. On the right are your Loops categories. Click on one of these to see individual loop details. All Drums is a good place to start.
Step 4: Missing loops?
If this is the first time you’ve loaded GarageBand you may find a bunch of missing loops. Click on the arrow here to download your loops for free from Apple.
Step 5: Follow the prompts
This interface will now appear prompting you to pick whether to download the loops now or later. Make your choice and then click OK.
Step 6: Fill it up
With your loops downloaded you can now simply drag and drop them into the main window in the middle section of the GarageBand screen.
Step 7: Quick copy and paste
Hold down the Alt key and you can drag a copy from your original loop allowing you to quickly stack them along the timeline and get building.
Step 8: Resize it
Use this slider at the bottom of the interface to zoom in and out of your arrangement. You can then see the whole structure of your song in more detail.