When the legs are in a slightly bent position and spread apart a little, you should be able to face them out about 45 degrees each and then just bend the feet a little so they can sit flat. He typically stands better if he's walking, one leg out in front of the other a little. You can always attach him to a baseplate too. But he's really not designed to stand with perfectly straight legs. Does that answer your question?
Jawa Costume from Star Wars
A LEGO® Built Micro Scale Set of Longmont Museum, Colorado by Imagine Rigney