Before the battle for Conan's soul, as the wizard is painting his hands, we see that this warrior and thief has very nicely manicured fingernails- which we also see on Valeria after the battle as she is running her hands over Conan.
Conan's mother is pointing the sword at the attackers' leader with both hands on the hilt. We cuts to a shot of Conan standing beside her holding her hand, then back to her with both hands on the hilt.
When Valeria reaches for the jewels after they first steal from the tower, her hand is faced downwards but when Conan grabs her and seductively moves the jewel over her, her hand is turned over so she can move her fingers towards the jewel.
While sneaking into the orgy, Valeria slowly and quietly makes her way over a low ledge on her way to the main area of the cave. At one point, her foot kicks a set of large hanging chains, causing them to swing. In the very next shot of her, presumably after only mere seconds of a cutaway shot, she is in the same position as last we saw her, but the chains are completely still.
When Conan is being beaten and tortured by Thorgrim and Rexor, in one shot you can just make out the bottom of Conan's father's sword positioned horizontally on the steps. A shot later, when Rexor and Thorgrim pick Conan up off the floor, the same sword is positioned vertically up against the edge of the stairs.
In one of the takes in the deleted scene showing Thulsa Doom's henchmen killing King Osric, one of them stabs him in the back, but there was no blood. Reason is because the guard missed the blood pack.
A few of the devotees holding torches toward the back in the night scenes at the end of the movie are swinging and looping their torches. Obviously they are having fun with the flame while they should be morning the loss of their leader.
When Conan's father is killed in the beginning of the movie, an axe is left lodged in his back before he is attacked by dogs. When the dogs are attacking him on the ground, the axe in his back is gone and there is no sign it was ever there.
After Conan cuts off Thulsa Doom's head and throws it down the stairway, the head is seen to stop rolling, still on the stairs. In the next shot, however, the head is not seen, but in later shots, reappears again where it had landed.