Hi there, Gaby here with an idea you can use to pretty up any envelope!  I used Tombow markers for this and a Wink of Stella pen.

I put a piece of card-stock in the envelope to keep any ink from seeping through the paper.

I started by using the Meet The Jelly Friends stamp set and did some masking to group three of them together. I used pigment ink here so my stamped image would not bleed.

I did my coloring here by doing the back ground first and then coloring in each stamped image.

I added my Wink of Stella and then used my Monotwin to fill in the part of my sentiment that did not fully stamp.

Finally, I cleaned up my image and then covered it with MicroGlaze, that way when it goes through the mail it will be water resistant.

If you do use MicroGlaze, write the recipient's address and apply your postage first because the glaze is almost like a wax.  I had to glue on a stamp once because I forgot!

I used the Mono Sand Eraser to clean up pills before I applied the MicroGlaze.  That's all for today, I hope you make some amazing mail art! Happy crafting.

-Gaby