There are several challenges going on (PTI and Penny Black) to use vellum, but I don't have the right stamps to enter there, so I have just been playing with what I have. I stamped the frame on vellum and centered the Cherry Blossom Bird inside it, clear embossing both images. Then I turned the vellum over and used my watercolor pencils to color in the details. When you turn it back over again, it gives a kind of stained-glass look. Then I trimmed the frame around the first rectangle, cutting out the fancy work.
Next I stamped the clouds background in blue on a piece of white cardstock and overstamped the frame in black, and trimmed it out the same way. This was then glued behind the vellum image, using tiny dots of glossy accents at the corners and the middle of each side, under the black stamping.
And lastly I stamped and clear embossed the frame again on a plain white card, then glued the above panel to the inside of the frame. The nest was stamped on white cardstock, watercolored, and cut out, then popped at the corner of the frame. I couldn't resist adding little pink pearl hearts over the hearts on the frame.
Here's a closer look; hopefully you can see the effect of the vellum colored on the reverse side:
supplies: white cardstock, vellum, Hero Arts S5324 Single Frame, S5215 Clouds, Stampabilities KR1061 Cherry Blossom Bird, Inkadinkado97104 (nest), Versafine onyx black ink and clear embossing powder, faded jeans distress ink (clouds), colored pencils, pink pearls