My T and I do a ton of different grounding techniques and she usually just works her way through a bunch until we hit on the one that works in any given situation. For me personally doing anything that gets me into my logical thinking brain works well, and physical stuff usually triggers another grounded part of self to come forward. Here are some of the things we do:
Roll a small ball back and forth to each other across the table.
Stand up and throw small balls back and forth to each other.
Each hold one end of a scarf and tug on it, feeling the pull and force as we tug and release.
Teach each other words in a different language.
She asks questions about aspects of my day at work (e.g. she asks me to tell her all of the actions I go through to set up for the morning when I first enter the building).
We play card games.
In a soothing voice she repeats stuff like "it is 2019. You are here in my office with me. It is safe here. None of that bad stuff is happening anymore. Its all in the past. You are safe now."
She gets me to look at different objects in the room and describe them to her in terms of shape, size, colour, function.
She gives me little grounding fidgets like slime, a cube, twisty things to play with.
I use aromatherapy oils to inhale.

There are a ton more things that I can't think of right now. We use at least several different kinds of grounding tools each session, and often we use some form of grounding tool throughout the whole session (like rolling a ball back and forth as we talk). She just tries a different bunch of them one after the other until she hits on one that works. She usually has to talk through to us first (It is 2019... you are safe here...) before a more grounded one can take over the body to engage in more intellectual or physically grounding skills. Then we keep using the intellectual or physical grounding skills to keep ourselves rooted in the present instead of switching into a trauma alter. Some days it takes a lot longer than others to bring us back, but most times we get there in the end.