Why not use margin? you can apply all kinds off margins to an element. Not just the whole margin around it.
You should use css classes since this is referencing more than one element and you can use id's for those that you want to be different specifically
i.e:
<style>
.box { height: 50px; background: #0F0; width: 100%; margin-top: 10px; }
#first { margin-top: 20px; }
#second { background: #00F; }
h1.box { background: #F00; margin-bottom: 50px; }
</style>
<h1 class="box">Hello World</h1>
<div class="box" id="first"></div>
<div class="box" id="second"></div>?
Here is a jsfiddle example:
REFERENCE: