Tags Widgets Dynamic with Custom Style

Step 01: Just add the tags widget from wordpress. It will look awful!
Step 02: Add the following code in functions.php

// Customize font-size of tag cloud widget
add_filter('widget_tag_cloud_args','set_number_tags');
function set_number_tags($args) {
$args = array('smallest' => 9, 'largest' => 9);
return $args;
}

Step 03: For better look, Add the CSS code in style.css:

.tagcloud a {
background: #3486BC;
border-radius: 2px;
color: #fff;
display: inline-block;
margin: 2px 0;
padding: 5px 10px;
text-decoration: none;
}