coping mechanisms i actually use
countdown: count backwards from five. seriously. the brain is naturally hardwired to worry, but ocd exploits that system. being absent-minded is when my ocd tends to strike the hardest. when you do something that requires even a minute amount of focus (like counting down or saying the alphabet), it literally shifts the focus in your brain to the frontal lobe. this technique is also really good for bringing yourself back to focus.
the five senses: hold your head still, and move your eyes around the room. list five specific things you see (light hitting a floor tile, the pattern on your curtains, the chip in your nail polish). do the same with four things you can touch, three things you can hear, two things you can smell (or imagine smelling), and one thing you can taste (or imagine tasting). this really helps bring me out of a spiral and back to the present. i've also noticed i prefer to write mine down.
identification: there is a pattern called the "thinking error cycle" that ocd plays off of. it says that a negative thought ("i'm contaminated") leads to negative feelings (anxiety, distress, panic) the feelings lead to physical sensations (tight chest, sweaty palms, dry mouth, raised heart rate) and then that leads to a behavior (washing hands). the issue is that it's a cycle. the behavior just reenforces the thought, strengthens the pattern, and starts the cycle all over again. i've found that it really helps me to map out where i'm at in the cycle and work my way back to the triggering thought. it helps to know i'm caught in a proven cycle, and tends to ground me a bit more.
rationalization: a lot of my intrusive thoughts revolve around illness and death, so it helps to write down rationalizations for the "symptoms". it's a lot harder for your ocd to convince you that you have a rare disease when you're looking at a list of reasons you physically can not have it.
square breathing: this helps me ward off oncoming panic attacks, or relax after one. breathe in through your nose for four counts (set the pace for slightly below your current breath rate, and progressively slow down), hold for four, exhale through your mouth for four, hold for four.
brain dumping: when you feel overwhelmed, journal. don't spend time on nice handwriting or proper sentences, just let your brain flow. the idea is to let your brain voice its concerns without the editing that normally goes into our communication. i bought a specific journal and pens to brain dump with, and always keep them in my bag so i don't have an excuse not to do it. mix it up with a different colored pen every time if it makes you happy. (don't feel pressured to do it every day! it's there for your benefit, so do it when you need to!)