a lot of you will probably rip on me for starting this thread, but it must be done.
for the newbies out there that are thinking of riding without the center fins (please don't call it "finless" if it has molded-in
FINS), please learn your fundamentals first before you even think of doing that. fundamentals doesn't magically happen by simply removing the center fins. sure, it has helped a few riders, but that's very rare. don't be fooled into thinking that's the easy way out.
master the progressive edge. you need a progressive cut in 90% of the tricks. once you've master the cut (both hs, ts, switch hs, switch ts), then take off/replace the center fins and start experimenting; with no center fins, smaller fins, long base fins, etc.
good luck.
(ducking as i step off my soapbox)