I am also in the 'end on a weekend' camp.
And find if I post too early in the morning (I am a 4:30 am waker... NOT a good time to list my chips on Ebay!) - or too late (after 9 pm), my auctions don't seem to do as well.

Shipping is a problem. I am getting dinged in my 5 star ratings because of $2 cost of shipping.
(I DO combine shipping for multiple wins).
Because of new postal rates and minimum rate for 'parcels', I am still fumbling with fair rates for single/ low end chips.

I also tend to pass on auctions that demand $3.00 + for one chip (although I did pay that this week on one.)

I miss the days when we stuck a .60 cent stamp on a #000.

I'll be watching this thread for tips too.