I used a bone folder to postion the yarn and lightly press it into the glue.
(I just use elmer's gel glue. It is water soluable so my tools are always easy to clean and it dries clear.)
Then I take my sharp scissors with pointy ends and snip the yarn to size.
Each piece is layed tightly against the previous one and before you know it, your design is filled in.
Feel free to change the textures and weights of the yarns in your painting and the directions you glue them in to add interest.
Just have fun!