I like when folks include information about the
character and/or what scene the cel is from, 
especially if it's from a series I've never
seen before.  A lot of times I find myself 
wondering why a collector chose that particular 
cel and ancedotal info is a great way to share
this peculiar hobby of ours.  I do not like to
post sequence numbers, though.  I don't 
watermark my images, but I keep them small on
purpose and don't send larger images unless I am
trading.  I will sometimes mention if a cel is
an end cel, but that's as far as I go.  I do 
love reading why a particular cel was purchased,
though! :)

Jen

(I bought the cel below because it's Duo (duh) and
I'm a total sucker for the boys in their suits!)