Use Ebay turbo lister.You can store listings on there and upload to Ebay when you like.
Also i personally avoid cheap listing days becasue alot of sellars will list that day and i have found i sell less.
As far as I'm aware you can't save your listings, but there are 'power' sellers so there must be a way of inputting a lot of items quickly, although I think that these are similar items. There are also a lot of prefilled info slots now,such as for CD's and DVD;s etc, you could certainly take all your snaps now, that seems to take the longest time in my recollection. Good luck!
If you practice, you will get good at it. I can list most items in 5 or 10 minutes or sometimes less.
Listing usually costs 15p (if list for starting price of under £1). So you are saving 5p. Bump up the postage cost by 5p if you want to still save the 5p, but list at your leisure.
Also, research your items by doing a search of completed items. ie if an item always gets a few bids and ends up going for £10, you might as well start it at 99p, safe in the knowledge it will get bid up to £10 as there are so many buyers. Very occasionally, you can come unstuck with this, but not usually!