Hi Fuzzybear. Here are some from a blog post I wrote a long time ago. Some specifically relate to depersonalization/derealization, but I'm assuming you're not looking for them, exactly. The rest apply for all types of grounding needs. A few have already been mentioned by others, but I left them in to show that they also help me.

Mental grounding

• Prepare for a stressful event in advance – If you know you will be entering a triggering environment, rehearse a sample conversation (or reassuring words) in your head ahead of time. Visualize yourself remaining grounded or making pre-planned movements or responses.
• Take a special note of your surroundings – Take a moment to zero in on something you’re familiar with (like a painting or a house along your route), and describe it in your mind or out loud (if appropriate).
• Distract yourself with a “game” in your mind – Sing a funny song in your head. Count to six. Listen to the tapping of your foot on the ground.
• Visualize a calming place that you’ve been to in the past – Remember the feeling of being at the beach and hearing the pleasing sound of the waves. Imagine being in bed hugging your pillow.
• Reorient yourself to the current place and time – Ask questions like what time is it? Who am I speaking to? What is my name? Where am I? Tell yourself that you are OK, despite the extreme stress.
• Pick your music and auditory environment right – I sometimes find myself drifting away from my surroundings listening to certain types of music. This can be dangerous when driving, riding my bike, or even walking. Some music/sounds calm and ground me, others affect me negatively.

Physical grounding

• Use your senses to keep yourself in the moment – Smell a flower, the room, the perfume on your wrist. Feel the softness of your alpaca sweater. Lightly touch or squeeze your arm or the steering wheel. Hold onto the sides of the chair you’re sitting on firmly and say “I’m here and I’m grounded.” Reach into your pocket and feel the piece of lint.
• Be aware of your breathing – Make an effort to hear your breathing. Breathe in at a slow rate and breathe deep. Recognize that the breathing is yours and that you control your body.
• Drink a sip of water, or other drink – Stay aware of your swallowing. Take notice of the taste and heat (or coolness) of the beverage. Clear your throat.