Requirements:
*Browser: Firefox or Chrome
*BRAIN!
*Charles Debugger.(Click here.)
(If you cant install Charles debugger. Download Java first. Click here.

1. Open Charles.
2. Open Farmville, then let it load.
3. Open Marketplace, choose Decorations, click Buy Haybale, don't place it yet.
4. Go back to Charles, look for [You must be registered and logged in to see this link.] right-click on the FIRST gateway.php and choose Breakpoints.
5. Now go to Farmville, put Haybale directly into Storage.
6. In Charles, An new tab will pop up. click on Edit Response then click AMF below. look for the word haybale and change it into item you want.
7. Chedeeng!! Done!! :)

NOTE: Please test on account with no coins/FV cash. This works for items that are not on Marketplace, and has no $ value.

Here are a few items that work:
treetinsel
resttentstriped
loungechair
picnictablecloth
firepit
treeswing
hottub
gnomegold
streamlinetrailer
watertowernologo
zengarden
chestoftoys
silvergoldgate
fountaingold
gnomesilver

These items may work,maybe not. Im not sure. Just try it.
spookytree
hollowtree
spookytombstone2
scarecrowlantern
bats
jackolanterns
jackocat
spookyplantmonster
tombstoneghost
spookyspiderweb
spookyironfence
spookyironarch
ufo
cropcirclebase
cropcirclecircle02
cropcirclecircle
cropcirclesmile
cropcirclecow
cropcircleduck
thanksgivingtable

Credits to Istroke and r2O-tricks