At the risk if piling on, a little rock climbing experience goes a long way. Climbing in the gym will help, but you won't learn routefinding skills. Practicing scrambling is great. You can build your skills and confidence without getting very far off the ground. An afternoon or two of top roping lower fifth class outdoors will make you wonder why anyone would stress over the final 400.
Downclimbing IS harder than going up, but that's mostly because nobody practices it. If you practice with a rope, practice climbing down without tension.
Bring good footwear. My trail runners were marginal last week. Many light hiking boots have reasonably sticky rubber. Approach shoes are light with sticky rubber. If the final 400 still seems intimidating, bring a pair of rock shoes.
