While you may do your auction in whatever format you wish, as long as you follow the rules above, there is a suggested format for you to follow to prevent any misunderstandings or issues that the rules do not cover. Here is a suggested format that you may copy/paste for your auction post. Reminder, you do not have to use this, it is just a suggestion compiled from many different users;
[b]Subject[/b]: <Name of item> <Enchantment(s) if applicable>
[b]Level Enchanted On[/b]: If unknown state "N/A"
[b]End Of Auction[/b]: <[i]Date[/i]> <[i]Time[/i]>
For the end time it's suggested you post both date and time, with timezone. Starting price is what you will accept as your bottom end for the item, so if you don't want a pickaxe to sell lower than 1K make sure you put your starting bid as 1K. The price increase is the minimum bid that each person can make, so if the increment is 1K and the current bid is at 5K, the next bidder must bid a minimum of 1K more, for a bid of 6K. This prevents people from bidding $1001, $1002, $1003, and so-on. A buyout price is the price you're willing to accept if a person simply wants to end the bidding war and buy the item direct. This should be what you WANT for the item, but it doesn't mean you'll get it. Of course, you only put in Enchantment information if the item is something that can be enchanted, otherwise you put "N/A". Notes is any additional information you want to give about an item. If it's a tool maybe your notes will be what enhancements it has and the fact that it's never been used. If it's a location, maybe a brief description of it.
NOTE: Some people will put a note in their auctions so they can cancel it at any time. However, that's not required due to auction rule number 4.