Best way to maximize Sneak Attack damage

Unchained Rogue

Sources allowed:

  • Core Rulebook
  • Advanced Player’s Guide
  • Advanced Class Guide
  • Advanced Race Guide
  • Ultimate Combat
  • Ultimate Magic

I’m asking for how to maximize damage output using Sneak Attack. In theory for all levels, but more specifically at level 1 through 6 or so. Whether it is using feats, magic items, (something I am overlooking?) or a combination of all of that, the objective is maximized damage output.

I don’t really want to multiclass, and want to focus on melee attacks, not ranged attacks. My character will use a shortsword.

I am just looking for maximum damage output, not how to create a ‘sneakable’ condition.