Re: Breeding Sandshrew
Well, it depends on what game you're playing.
If you're playing Fire Red/Leaf Green, to build a Sandshrew with both Rock Slide and Swords Dance you just need to talk with the respective Move-Tutors. It's pretty easy.
If you're playing Ruby/Sapphire/Emerald you could ask a friend to trade a Sandshrew with those moves included in the moveset, but I don't think he was going to waste Move-Tutors on a Pokémon he's going to trade away.
But if you want have a Sandshrew from breeding with this moves, then I have to say you that there's no a breeding that will provide you both moves in only one moveset.
But if you choose a move, you can have so a male Absol/Camerupt with Rock Slide or Larvitar with Swords Dance, so just catch a female Sandshrew to breed and the other move you take from a move-tutor.