To make my card, I made the blue background first, attaching it with double stick tape. Using the four images to judge the size, I cut four square mats for them out of the same blue card stock.
The size of those four squares determined the size of the pick mat behind them, and then I centered it on the card. The remaining stickers from the April set fill in the empty space around the large images. Lastly, the sentiment overlaps the top two squares, tying them together in a cute way.
Use the images themselves to make the first square, then cut them all the same size. Center the images in each one and attach them to the front of the card in an offset checkerboard pattern. Then fill in the open spaces and add the sentiment.
Once you've tried this layout, I'd love to see it! Have fun and take a few pictures of the finished product.