I wrote a fairly in depth post on some of my ideas about a week ago, linked to here for those interested.
The TL;DR version as well:
- More gems. Skulls and diamonds would be awesome. Skulls give life steal (weapons), LoH (helms) and armor (armor/other). Diamonds give attack speed (weapons), dodge chance (helms) and all resist (armor/ other)
- Give breaking down items a chance to yield a unique equip socketable glyph giving one of the affixes of the item it came from. Glyphs have a set durability and cannot repaired
- Remove sockets as a random magical affix and allow the jeweler to add sockets for a gold cost, in addition making the socketed item account bound (but still able to be broken down for crafting materials). This allows the socketing system to enable lots of gearing diversity and act as an effective item sink
- Add a 3rd type of socketable items, runes, also unique equip, that give affixes that can’t otherwise be gotten in game. Examples include Pierce Chance, Mulitshot Chance, Chance to Proc D2/LoD skills, Increased chance to spawn health globes