I am using this ViewScript for my standard form elements:

<div class="field" id="field_<?php echo $this->element->getId(); ?>">
   <?php if (0 < strlen($this->element->getLabel())) : ?>
      <?php echo $this->formLabel($this->element->getName(), $this->element->getLabel());?>
   <?php endif; ?>
   <span class="value"><?php echo $this->{$this->element->helper}(
      $this->element->getName(),
      $this->element->getValue(),
      $this->element->getAttribs()
   ) ?></span>
   <?php if (0 < $this->element->getMessages()->length) : ?>
       <?php echo $this->formErrors($this->element->getMessages()); ?>
   <?php endif; ?>
   <?php if (0 < strlen($this->element->getDescription())) : ?>
      <span class="hint"><?php echo $this->element->getDescription(); ?></span>
   <?php endif; ?>
</div>

Trying to use that ViewScript alone results in an error:

Exception caught by form: No file decorator found... unable to render file element

Looking at this FAQ revealed part of my problem, and I updated my form element decorators like this:

'decorators' => array(
   array('File'),
   array('ViewScript', array('viewScript' => 'form/field.phtml'))
)

Now it's rendering the file element twice, once within my view script, and extra elements with the file element outside my view script:

<input type="hidden" name="MAX_FILE_SIZE" value="8388608" id="MAX_FILE_SIZE" />
<input type="hidden" name="UPLOAD_IDENTIFIER" value="4b5f7335a55ee" id="progress_key" />
<input type="file" name="upload_file" id="upload_file" />
<div class="field" id="field_upload_file">
    <label for="upload_file">Upload File</label>
    <span class="value"><input type="file" name="upload_file" id="upload_file" /></span>
</div>

Any ideas on how to handle this properly with a ViewScript?