I like to use fun emoticons from here:
Select which emoticon you want, then right click and copy; then come over to the thread you want click on Post Reply and in the toolbar there is an icon called "Insert Picture From Web (Link)". It's the one that has a chain link at the bottom of the yellow square. Then paste into "Picture Source". Delete [IMG] out of the front and back of your link. Select OK and it will appear in your message. Like this:
And off you go!