It’s actually super easy to activate emoticons or emoji’s or smileys or whatever you’ll like to call them on an iPhone or iPad. It seems that Apple have set up a native “International Keyboard” dedicated to emoticons which houses a pretty extensive set of emoticons.
Go to Settings > General > Keyboard > International Keyboards
Click on “Add New Keyboard…” and select “Emoji”
Your QWERTY keyboard will now have an additional button next to the space bar as shown here:
If you click on it once, and your keyboard will switch over to the Emoji list or you can click and hold it to allow for a full list of the active keyboards to be displayed.