I constructed my base card by welding two tags from TBBM. I then laid out my gate with the capital letter "I" from the wooden letters on Pooh Font cartridge and overlaid the same arched top tag. The lock was created using the rounded-corner rectangle from the George cartridge as was the keyhole -- I made it using a small circle and a rectangle.
The bird is from the Create-A-Critter cartridge -- and I know . . . this is not a robin. However, the brown robin just didn't stand out against the brown gate so I improvised! The ivy is from Paper Doll Dress Up.
I stamped an antique key on the envelope flap with a russet brown stamp pad. The envelope looked like it had been made with old parchment paper.
The card base is ivory card stock and measures 5 1/2" x 4 1/4". The gate is Bazzill Basics brown; the ivy is also a Bazzill paper and was stippled brushed with an evergreen stamp ink; the bird is cut from two shades of Bazzill and I used chalk on his chest. The lock was cut from a metallic gold paper I've had for forever.
Party decorations were pretty simple - a banner, two centerpieces, a butterfly "chandelier" and some tissue paper pom-pom flowers (that we ended up not hanging) that I made; and paper lanterns from the $1 store.