Using your senses to connect you back to the real world. They vary from quite ethereal to practical, depending on your tastes. Personally, I to do things like
- 3 things I can see, 2 I can feel, 1 I can hear
- run my hands under cold water
- things I can see that are blue (a common colour; might need to do grey if outdoors in a town or green if in nature)
- identify the different objects around me (sometimes very basic like wall, chair, carpet etc!)
There are LOADS of techniques out there. You can adapt each one to you tastes. My 3, 2, 1 is taken from a 5, 4, 3, 2, 1 as it's also meant to include taste and smell but my taste and smell are rubbish so no good in this situation. They're meant to be quick and easy and very a little bit more difficult as you "come to". If you can't answer, skip it and move on. If you overwhelm your brain, it'll retreat back into disassociation. If you keep it too easy for too long, it'll stay in in the comfort zone.
Some people respond better to touching things, some do better from looking and describing, some from listening. We're all different and there is no right way, so long as you're slowly inching forwards along that precarious rope bridge.
Disassociation, incidentally, is your brain's way of protecting you. Coming back to reality is a bit like tempting a frightened cat down from the top of a tree.