You absolutely do NOT need any nail art tools to do this. I used a q-tip and coconut oil.
I painted my daughter toe-nails any color she wanted (she chose "rainbow") and then added her decoration of choice with a wet q-tip. I dabbed the q-tip in the glitter and or shape and applied it to her nails before the base coat dried. I added clear nail hardener on top for the finishing touch. It came out great. I use coconut oil to clean the possible chance of coloring outside the lines. ;p