Ways to grasp your players attention

Kill something or someone. It can be an anonymous NPC, a friend of the PCs, or the wizard’s familiar. Geez, I hate familiars. They’re really annoying.

Give everyone a fix of caffeine. Energy drinks and coffee can work wonders.

Whip out a gun. It’s a way to say “show the PCs an immediate death threat”. Anything that puts the life of one or more PCs in jeopardy is good.
If your players suffer from an addiction to gamer’s crack and keep fidgeting with dice you might need a D&D chip & dip bowl.

Go psychedelic. One of the PCs starts hallucinating stuff - realistic or downright crazy hallucinations, it doesn’t really matter. You can come up with a reason for this after the game.

Introduce the campaign mysterious nemesis as charismatic, charming. Maybe he could send the PCs a note of apology because they have opposite goals and he might get in their way. Just go against the usual flow of the campaign. Fight the familiar!

Use something from one of the characters’ background. They liked their characters. They worked hard on them. Use their work.

Throw dice.

Take a break. Not ideal for game flow but can revitalize the players and the session.

Well, I always liked having up my sleeve, the option to improve a magic item by imbueing it with a personality. If the wielder does something extraordinary or important in the campaign/adventure context then bringing to life an ego-possessed item is always good fun. This suggestion in a way is similar to the advice given with the iconic 1E AD&D rings of elemental control whereby they can start off as simple items and later come to be much more powerful as befits the current challenge. This can be useful with a quiet/new player as it helps them roleplay and get into the action.