I have trouble with this too. All too often /i notice my session start will rather vicious chip bleed because of this, then I spend the next hour clawing my way back positive (I usually do though).
What i really wish existed was a place people could play poker seriously for about 10 minutes before a session without wagering anything. But we all know play money play is anything but serious.
With the absence of that, I put on music, get comfy, and try to take everything real slow. take a couple orbits of being really really tight and just getting accustomed to the table.