Snippet of abandoned checkout notification, informing customers of discount - https://www.shopify.com/partners/blog/shopify-email-notifications

email-notification-discount-text.liquid

{% capture email_title %} Your shopping cart is waiting for you {% endcapture %}
{% capture email_body %}
{% if billing_address.first_name %}Hi {{ billing_address.first_name }}, w{% else %}
W{% endif %}e noticed there {% if item_count == 1 %}was an item{% else %}were some items{% endif %} left in your shopping cart.
If you're ready to complete your order, your cart is waiting for your return, and you can even have a 15% discount on us. 
{% endcapture %}