|What I used.|
I used Orly's Velvet Rope as a base, then Wet N Wild's Show Me the Money (SMM) just on the tips of the middle, ring and pinky fingers, and one lemon fimo art piece for the ring finger. I dabbed SMM starting at the tips and then dragging the glitter towards the cuticle, for a gradient effect. Its like painting on regular nail polish, but with less polish, a little cuticle drag and instead in the opposite direction. You probably could use a sponge and sponge the tips, but this worked well for me. Plus I didn't have to clean up any sponges afterwards.
To add the lemon fimo: I just dabbed a small dot of top coat on the nail where I wanted to place the lemon. Then I dabbed some top coat on one side of the tweezers to pick up the one lemon slice, placed the slice on top of the dab. I then used the tweezers to press down on the sides of the lemon slice to make sure the slice was resting as flat as possible. Finally, I painted on thick coat of top coat over the whole nail.
I bought my lemon fimo art at Sally's and they are pre-cut, they look about 1/2 mm thick. Which is still a bit thick, I can still feel it on my nail. I would imagine the fimo would break too easily if they were thinner. Anyhow, they were $3.99 for the small vial. I think it's a little pricey for what they are, but oh well they're really cute and I didn't have to cut them. Plus, the small amount will last me a long time because I'm not the type of person who wants to pile 4-5 pieces of fimo fruit on each and every nail. Have you see those manicures?
If not, just type in "fimo fruit" in youtube's search box and you'll see the monstrosities I'm referring to.