(0.9) What do I do to ensure that none (or as little as possible) of my items break when transferring to 0.9?

I'm really interested in playing 0.9, but I've told myself to wait for a more stable build, BUT I WANNA PLAY SO BAD!! The only thing stopping me has been that, from what I've seen and heard, the game will turn most items in your mailbox into large ERRORS. I know there's a setting that is meant to fix it, but apparently that only fixes a few items.

What are the steps I need to take to save as many items as possible? I have quite a few items I REALLY do not want to lose since I've had them since around 0.6!

Here's (most) of the stuff I currently want to take to take to 0.9