Lessen Gap Between Widget in Sidebar

If your theme has a built-in custom CSS option, use it; otherwise, get a custom CSS plugin and put:

.ig_widget {
	margin-bottom: 5px;
}

If that’s still not enough, try this code instead:

.ig_widget {
	margin-bottom: 5px;
	padding-top: 10px;
	padding-bottom: 10px;
}