You can use Btsync to sync files between folders on different devices. It works really simple. After installing, you create a share by selecting a folder and creating a code. It's easiest to start on the laptop. Create a new folder for the syncing, and copy files to this folder. If another device deletes files here, they might be lost on all devices so you should only use copies here.
When you have created the first share, link you phone to it. From the laptop you can scan a QR code for the secret key. On the phone you use another new folder. You can sync automatically, and you can sync manually. You can set to sync only over wifi or over 3G as well.