So I have put some money in my TFSA.  How do I time buying ETFs as they are basket shares?

I have some some normal shares and my my naive strategy is to buy blue chips when they dip and hold for the long run.  For example I am buying MTN as I believe that their fundamentals are good but they have been wacked by fines so sentiment must be bad but they are still paying a 5% divident.  I see Tinger brands has also taken a hard nock.  Then I took a gamble and put a few grand on Steinhoff and Lonmin.  Is this strategy completely foolish?