What is the better way of using value-Templates

Configuration Frontend
,
1

Hi out there,
what is the best practice for using value-templates?
Example sensor.yaml file:

- platform: waste_collection_schedule
  name: "Gelber Sack"
  value_template: "{% if value.daysTo == 0 %} Heute{% elif value.daysTo == 1 %} Morgen{% else %} in {{value.daysTo}} Tagen{% endif %}"
  types:
    - Gelber Sack

I would like to use the sensor status in different cards.
Is it better to run the template in the sensor.yaml or in the card first?
What if I want to modify (style) the card ?
What are the (dis)advantages in your opinion ?
I want first to collecte some thoughts.
Many thanks in advance !

So long
Pc