Begin by standing on a comfortable surface where you have plenty of room at each side.
With a 5-lb. potato sack in each hand, extend your arms straight out from your sides, and hold them there as long as you can. Try to reach a full minute, and then relax.
Each day you'll find that you can hold this position for just a bit longer.
After a couple weeks, move up to 10-lb. potato sacks. Then try 50-lb. potato sacks.
Then eventually tr y to get to where you can lift a100-lb. potato sack in each hand, and hold your arms straight for more than a full minute. (I'm at this level.)
Once you feel confident at that level, put a potato in each sack.
A man sits in a bar and every so often he pours a little beer in his hand. The bartender asks him, "What are you doing?". He replies, "getting my date drunk.!"