Multiple Line Breaks
The <br/>
tag is for enforcing a line break, where you don't trust
the browser to do what you want. However, you never need more than
one. If you put more than one line break, you should rather use a
block level element that will produce the space you want.
Hence, this is just plain non sense:
<p>
My text
<br/>
<br/>
after some space
</p>
Instead, just start a new paragraph:
<p>
My text
</p>
<p>
after some space
</p>