Love this topic
When I'm on tilt or about to go on tilt I do as much as I can to get into a relaxed state. In my view tilt is caused by tension buildup that we are unable to release.
Quick fixes include
-Deep breathing
-Intentionally relaxing muscles
-Getting up and walking around
-Shaking things out
-Stretching
-Putting things into perspective
-Engaging gratitude/thankfulness
-Closing my eyes and counting to 10
All these things help to go from a highly focused, highly active, highly stressed state, to one that is much more calm, centered and relaxed. As I get into this state I realize that it's ok to miss a hand, to take a 5 minute break, to disconnect for a moment so that I can digest the experiences which are overwhelming me and making me feel uneasy. Once the processing is done then I can return with a fresh slate ready to play my best poker again
For longer term solutions I made this video
https://www.youtube.com/watch?v=Of-owVCW6kI
And for really long term work, I invest time with a therapist to unravel the deeply routed issues that are causing subtle tilt on a deep level. Combining this process with a health active lifestyle helps me to move all the old energies thru that make it easier for me to tilt, and I'm finding day by day, month by month, year by year I become much less affected by anything that happens on the poker table.
A good question to ask when feelings of tilt arise is "why does this bother me so much" and that will start you on a good process to finding the root cause
Also highly recommend Jared Tendler's "The Mental Game of Poker" it's an amazing book for tilt issues, I read it back in 2013 and it helped me a ton!