I prefer auctions that end either 24 or 48 hours after the last bid has been placed. That makes last-minute bid-sniping impossible, and auctions only go for as long as people are interested in bidding on them. Sometimes that means that some of the auctions will end kind of quickly (i.e. in a day for two) if only one bid ever gets placed, while other more popular auctions may go on for several days if there are multiple bids spread out over time. However, in every case everyone gets a fair chance to bid on them, and you never have to worry about losing a character because you overslept or are at work for something because any bid placed extends the ending time of the auction.

Just my friendly and hopefully helpful suggestion!

I like that idea, I'll probably do that when I get around to posting the adoptables I have (hopefully in the coming week)