{% load widget_tweaks %}
<div class="container">
<div class="col-md-6">
{% render_field form.field1 class+="form-control myCSSclass" placeholder="Placeholder for field1" %}
</div>
<div class="col-md-6">
{% render_field form.field2 class+="myCSSclassX myCSSclass2" placeholder=form.field2.label %}
</div>
</div>