For the patterned paper, I recommend that you find a pattern that you like both sides and cut it down to a 4 1/4"x11" piece. Then cut it diagonally from the top right down to the bottom left just like you did the score line on your card. Then slowly cut it down into the shapes you need.
The card will fit in a standard A2 envelope but you do have to put it in correctly. The first time I tried, it was about a 1/4" longer than the envelope and I panicked! Then if you just turn it about 45 degrees, it fits in just fine.
Here's what you will need to duplicate this card:
Stamps: Greetings of the Season & Every Little Bit (snowflake on front)
Inks: Versamark & Cherry Cobbler
Paper: Gumball Green, Very Vanilla, Be of Good Cheer Designer Series
Paper & Champagne and Red Glitter Paper
Other: Gold Embossing Powder, Snow Flurry Die & Labels Collection
Framelits, Jumbo Rhinestones