This module example template render form

my_module.info

name = My Module
description = This module exmaple
core = 7.x
version = 1.0

my_module.module

<?php

/*
 *  Implements hook_theme()
 */

function my_module_theme()
{
    $items['page_user_edit_add_form'] = array(
        'render element' => 'form',
        'template' => 'page-user-edit',
        'path' => drupal_get_path('module', 'my_module'),
    );
    return $items;
}

/**
 * Implements hook_menu().
 */
function my_module_menu()
{
    $items['admin/henry'] = array(
        'title' => 'Henry Module',
        'page callback' => 'drupal_get_form',
        'page arguments' => array('page_user_edit_add_form'),
        'access arguments' => array('access content'),
        'type' => MENU_NORMAL_ITEM,
    );

    return $items;
}

/*
 *  Create form
 */
function page_user_edit_add_form($form, &$form_state){
    $form = array();

    $form['hovaten'] = array(
        '#type' => 'textfield',
        '#title' => t('Fullname'),
        '#description' => t('This field input fullname')
    );
    $form['submit'] = array('#type' => 'submit', '#value' => t('Save'));

    return $form;
}
/*
 *  Process submit form
 */
function page_user_edit_add_form_submit($form, &$form_state){
//code submit
}

page-user-edit.tpl.php

<?php
// $form = drupal_get_form('page_user_edit_add_form'); Không nên làm cách này
print '<form id="'.$form['#id'].'" accept-charset="UTF-8" method="'.$form['#method'].'" action="'.$form['#action'].'">';
print render($form['hovaten']);
print render($form['submit']);
print drupal_render_children($form);
print '</form>';