Hydraulic Press safety questions

What types of safety cautions do you guys take when using a press? I bought one of those 20 ton presses from Harbor Freight last year and it works great but I always have that uneasy feeling that piece I'm pressing or the extension I'm using is going to fly out and do some major damage. I imagine it could kill you if enough pressure is built up.

I've been sanding to the side of the press since the metal frame is there to protect somewhat. Now I'm thinking of maybe laying some thick metal on the side of the press so nothing could get through when standing there.

Any other ideas or anything you guys use or am I being overly cautious?