You can actually do the following:
In layout.html.twig (or whatever your layout is)
{% block stylesheets %}
{% stylesheets 'your_assets_here' %}
<link rel="stylesheet" href="https://stackoverflow.com/questions/6958970/{{ asset_url }}" />
{% endstylesheets %}
{% endblock %}
And in any template that extends that layout:
{% block stylesheets %}
{{ parent() }}
{% stylesheets 'additional_assets_here' %}
<link rel="stylesheet" href="https://stackoverflow.com/questions/6958970/{{ asset_url }}" />
{% endstylesheets %}
{% endblock %}
Then you wouldn’t need to retype all the old assets as suggested by Nemanja Niljkovic