Funny you know, I made myself up a 'sandbag' out of a truck inner tube that weighed in at around 70 lbs.
Since I can OHP double that, I thought it would be no problems. So I put together a circuit similar to this one (but with a few 'curl & press' and lunges thrown in).
The next day I cut the tape off one end and emptied out around 20 lbs of sand..
The sand bag is great leveler.