I would suggest looking for what you think are "good" companies as opposed to any Cap or share Price value for what might be considered a penny stock. Some really good (by my definition) companies are penny stocks as are some really bad ones - I have owned both types.
first figure out what you mean with penny stocks, if you talking about the small 1c, 2c things, just know you will lose money for a long time before you make anything (if you make), especially in SA where the liquidity is super low. My advise would be to stay away specifically from the REAL penny stocks However you can follow Keith McLahlan who runs the Alpha Small cap fund He has his own blog and good track record. It focuses on small caps which have a slightly better following at least. http://smallcaps.co.za/blog/home/
I don't know about that so much? Keith Maclachlan has been doing an excellent job in this sector for years. http://smallcaps.co.za/blog/home/ Admittedly small caps though, and not penny stocks. With regards to penny stocks, this is a difficult sector to trade. The strategy has to be based on a 7 out of 10 will fail, philosophy, which is fine, if one of the 3 is FGL or Sacoil (in its heyday). But the rest of your bets you would have to be prepared to lose it all (as per Beige, RBL, Platmin, etc etc.).
There are fewer and fewer companies that will "make it" in this environment - or for that matter survive. As for MacLachlan - he isn't a penny stock pundit - as you admitted. Regardless, I don't give him much chance in this market (going forward.) His track record???