I would make check boxes into images, see fiddle https://jsfiddle.net/0c26tqd7/1/
edit I added a red border on checked check boxes in the fiddle
html
<input type="checkbox" name='thing1' id="thing1"/><label for="thing1"></label>
css
input[type=checkbox] {
display:none;
}
input#thing1[type=checkbox] + label
{
background-image: url("http://lorempixel.com/50/50/");
height: 50px;
width: 50px;
display:inline-block;
padding: 0 0 0 0px;
}