Expression is any your posts with a variety of emoticons. So that readers can more feeling what you feel when you write. There are emoticons from Blogger, Yahoo, and Union. For Blogger Emoticons I already gave you here. For Union Emoticons, I will give you in the next post. To adding emoticons to post, very easy. You only need to add some HTML codes on the HTML Tab(Not in the Compose Tab). This format code is:
<img src="http://YOUR-IMAGE-URL" width="18" height="18" border="0">
Or if you not understand about the format, you can read here.
The emoticons codes are:

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/1.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/2.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/3.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/4.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/5.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/6.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/7.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/8.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/9.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/10.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/11.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/12.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/13.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/14.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/15.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/16.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/17.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/18.gif" width="34" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/19.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/20.gif" width="22" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/21.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/22.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/23.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/24.gif" width="30" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/25.gif" width="30" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/26.gif" width="24" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/27.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/108.gif" width="31" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/106.gif" width="40" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/107.gif" width="52" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/49.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/50.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/51.gif" width="21" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/52.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/53.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/54.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/55.gif" width="25" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/56.gif" width="17" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/57.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/58.gif" width="30" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/59.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/60.gif" width="20" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/61.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/62.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/63.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/64.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/65.gif" width="22" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/66.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/67.gif" width="22" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/68.gif" width="22" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/69.gif" width="26" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/70.gif" width="23" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/71.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/76.gif" width="36" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/77.gif" width="32" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/78.gif" width="26" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/79.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/72.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/73.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/74.gif" width="18" height="18" border="0">

<img src="http://us.i1.yimg.com/us.yimg.com/i/mesg/emoticons7/75.gif" width="18" height="18" border="0">
Or you can download all here. Happy post and Good Luck! See you in the Next Post!
Very valuable idea