Ok, so I've been speedcubing for about 6 months now and I average around 20 seconds on the 3x3. Is it possible to get my times down to sub 15 seconds average by the end of this summer? If so, what do you suggest I do to practice? I use CFOP and know all of the PLLS, but only 15 or so OLLS. My F2L time is around 15 seconds. Any and all help would be appreciated.