Sticker Mock ups with wood looking background - dogs

I have a number of designs that I am using for stickers. I am building a sticker store and am looking to do a few mock ups with dark wood back ground to show off the designs (as stickers). I will be doing a general listing showing a few of the stickers as they are for sale and then show some mock ups of how they would look on computers, water bottles or on phones. The problem I am having is creating the mock up showing all of the available designs. I've seen other sticker stores and their mock ups look realistic. I do not have the computer knowledge or time to try and create it myself. I ordered some background downloads, but placing each design in on the wood background doesn't look as good as examples that I have seen. I am attaching the style I am looking for. All of my designs (Aruba dog and cat themed) need to have separate wood background mock ups for each group. I plan to have dog stickers on a set (I have too many designs to be able to place on one background) and then cat on another. This is for the dog designs. All of the designs I plan to mock up with a dark wood background are attached as well as examples I have seen. I'd like the mock up to look realistic and have some shadows under the sticker (like the examples).