There are lots of great tips and pointers on this thread. I have summitted 22 times over the past 20 years, and to me the single most important thing to do is acclimate (which has been mentioned several times).
I like to drive up and camp and hike at Onion Valley for a day or two, then drive down to the Portal and spend another night before getting up early on the summit day. I would recommend two or three full days at altitudes over 9,000 feet if you want to improve your odds.
One other point - if you are planning to return in October - please be aware that October can be winter time in the Sierra. You are really taking your chances at having weather conducive to success.
Good luck! It will all be worth when the hut is finally in sight and you reach the top!
