I host two giveaways a month, for about 15 days each. If you have two of the items you're giving away, then sure - make a listing! But don't if it's OOAK - what if it were to sell? *bites nails*
The best advice I can give you is to submit it to giveaway blogs and Linky's. Here's a list of ones that works for me ~
I start a giveaway every Saturday and end the following Saturday. Of course I am hosting for tons of shops/companies not just my own. I find running them for one week is less confusing for me. GREAT links above!! :)