I thought I would just tidy up the solutions and add a video guide into one solution to make it easier to read, credit to those who already posted.
To gain this achievement you will need xbox live gold membership. Im sure you will have a 48 hour trial sitting around somewhere....
******If you're NOT going to do it with a friend.******
Firstly you will need to change the options of the game so that you can see everyones online Orbs instead of just your friends Orbs. The achievement may say send a gift to a friend but this is not actually the case, it can be sent to anyone. To change it to everyone; Press Start > Options > Game > Online Orbs > Everyone.
Now you need to actually find an orb. Just simply run around Bowerstone Market and you should find one easily. It took me less than a minute on a sunday morning.
Approach the Orb and press LT, an option should now show saying "Press A to interact". Do it. Now you can go down to gift, press A, then send them anything you want, gold or item. POP Achievement Unlocked.
******If you ARE going to do it with a friend.******
You can just simply either invite your friend to a game or meet them as an orb. To enable online orbs go Press Start > Options > Game > Online Orbs > Friends.
You can then approach your friend and press LT, an option should now show saying "Press A to interact". Do it. Now you can go down to gift, press A, then send them anything you want, gold or item. POP Achievement Unlocked.
VOTERS: Please tell me how to improve before voting negative.