Painting
Prime the decoy with Kilz primer and then paint it according to some reference pictures. I can not emphasize the importance of reference pictures enough because they are what will make your new decoy look correct. Painting is not hard but you have to make sure you have the colors in the correct place. Starting out, you just need to block in the basic colors. As you get more experience painting, you can add as much detail as you want. You can use any type of paint from common house paint to artist paints. As your skills with a paint brush improve, you will find that artist paints give you the best color matching but they are more expensive.
I have done this Bluebill in basic colors as it is strictly a working decoy. The head is one of the Restle heads we sell on the products page. I also added a keel to the bottom, which will help the decoy ride correctly and act as a anchor point for the bolt which is attaches the head. I prefer to use composite decking for the keels on these decoys because it does not need to be treated and it adds weight without having to insert lead in the keel.