One of the biggest helps I have found is guided meditation. There are so many apps out there you can download to your phone. I use 2. One is headspace that I pay for and the other is called smiling mind which is free. I find if I try to meditate on my own when really struggling with my anxiety and depression my mind will wander to what I'm trying to avoid. However, the guided meditation provides enough distraction to hold my attention.
Simply focusing on your breathing may sound silly but it can be extremely effective. Try counting 1 when you inhale, 2 when you exhale, 3 inhale, etc up to 10 then start the count again. Focus on how the breath feels, where in your body do you notice it the most? For me it's the rise and fall of my chest and the tingling in my nose when I exhale slowly.
Another issue I have is my whole body feeling tight and tense when my anxiety flares up. For this I focus on tensing parts of my body as tight as I can and then slowly relaxing and constantly concentrating on the difference between the two feelings. I like to start from head to toe so start by bringing my shoulders up to my ears, then tensing arms and balling hands into fists, then stomach muscles, glutes, thighs, calves then curling my toes. For me this is a way I show myself that I have control over my body. Regaining that sense of control is very important for recovery.