In order to create a new card in a list easily, just put your cursor over a card and press N. This will create a new card in the list nearest to your cursor.
Sorry for the bad quality
2. Put cursor over a card and press Spacebar to automatically subscribe
In case you have a hard time clicking on the card, searching your name up in the subscribe bar, and clicking your name in, you can simply press Spacebar to do all that task at once!
3. Put cursor over a card and press "D" to set due date.
This is another way of opening the due date calendar instead of clicking the card and manually opening it.
4. Put cursor over a card and press "C" to archive card
5. Press 1-9 to quickly add a label to the card
Those were 5 quick trello short cuts you could use! Thank you!