Okay, I'm fairly new to Aikido, but I'll have a stab..
1 - Evasion, then even if you fluff the rest at least you haven't got a knife wedged between your ribs... (Note the Tomiki influence there
2 - Ukemi, definately important but from the sensitivity side of things - and learning to trust yourself
3 - Lots of very hard warmups, so you can run like the clappers!
Okay, 3 is only semi-serious, but it's still a valid technique - since you'll be more relaxed in any situation you feel you can exit quickly from, thus less likely to get into anything 'confrontational' - something a lot of people forget to talk about when they're discussing Aikido..
My 2p worth