LF is fine for right-spin (same goes for LRF/RF in opposite spin directions) - the star pattern doesn't have too much of an effect aside from the awful noise. Of course, RF, R2F, or LRF would all be much, much better, since the rubber helps manage recoil well and makes your Beyblade move faster. Also keep in mind that LF is the only plastic flat tip that's at the same height as the rubber flat tips, so if you do use any other plastic tip, you should compensate with a taller Track.
I would suggest using CF (which is pretty much a direct upgrade to WF), since XF-sized plastic tips (like LF, GCF, and XF itself) can be hard to control and may self-KO. GF pretty much has to be weak-launched, so that's not a good idea either. MF is also good, if you have it.