I prefer to use "tools" that I already have. I try not to buy everything I see, although it is is sometimes hard I can usually stop myself. My storage space is limited so I do the best I can with what I have 80% of the time. For the surfboard I used a petal cutter from my Wilton 32 piece kit.
1. Roll out fondant @ 1/8" thick. Use cutter and cut your shape out.
2. Using a sharp knife cut the bottom of the petal off
3. Roll out a coordinating color and cut a long stripe about 1/4" thick.
4. Apply gumpaste glue or vodka with a brush to glue your stripe on your board.
(please excuse my fuzzy photo.. hard to take pictures of yourself doing fondant work without a tripod)
5. Attach the stripe to the surfboard & trim on both ends where it hangs over the edge of the board.
6. Trim the left & rigth side of the board to make it a litle narrower than the petal cutter cut. It's easier to do this after you place the stripe.