Plasma Donation

So the only time I've successfully donated plasma I passed out afterwards. They did give me Gatorade after my donation but by the time I got to my car my heart started going crazy and I lost conciseness.

I'm pretty poor so of course I still went back. I'll take the risk of not feeling well afterwards. But when I came back something was always wrong- my temperature, my iron level, my heart rate.

I've left it alone for about a year but I'm wanting to try again.

What are your tips for the donation process? I know they say drinking water helps speed up your donation and to not go in while sick but what else?