I usually spend a little bit of time coming up with a plan with my T before she leaves. Usually it's a list of things to occupy my time, things that will be pleasant, things like journaling or meditation that might help me deal with whatever feelings come up. I like to formulate the plan with my T so then it feels like she is part of it when I do things while she is away. Sometimes I plan an interesting knitting project and then bring it in to show her the finished project when she gets back (I started knitting initially because it is good for anxiety). My T will also usually give me a transitional object from her office if she's planning to be away and not available via phone or email.