Here is how the holiday decorating begins in The Amazing Valentine's Day.

At the Golden Oak Library, Yuna and her friends started decorating the supplies for the party.

Princess Yuna: Let's see now.

Somnambula: I trust you're looking forward to this occasion, Princess Yuna?

Princess Yuna: Yes, It's going to be the best party ever.

Somnambula: Yes, A most heartwarming emotion the anyone or anypony would treasure until the very end.

Dipper Pines: You sure spoke some riddles, Somnambula.

Somnambula: I know, Dipper.

As for Rockhoof, He brought out a special mighty helm heart shape rock.

Rockhoof: What'd ya think of this, Sugar Apple?

Sugar Apple: Very nice.

Star Swirl the Bearded: Twila, Would you like to help me and Mistmane with some snacks and drinks?

Princess Twila: Would I!?

Stygian: Yes.

So, Twila and Stygian help Star Swirl and Mistmane with some snacks and drinks.

Thunder Spectrum: Flash, Is this scenery high enough?

Flash Magnus: That's perfect, Thunder.

Somnambula: Very good.

When the sign was put up, It says "Happy Valentine's Day and Hearts and Hooves Day".