A method which I have been using for several years now is the following:
Utilising access to DFS you choose:
1) DFS Rating Top pick(preferably 18 or 17 points)
2) Time Rating Top pick(on DFS sheets)
3) Nominated as "late mail" selection in your particular state or whichever service you have access to.
This will definitely give you a "run for your money," particularly when investing in the ratio of 1x5 units.
My other "hobby" is system analysis and development and while being wary about the claims of some system sellers, I believe that with a solid "mechanical" selection method accompanied with an effective staking plan a punter can return long-term capital growth.
The point I make in respect of investing in the ratio of 1x5 is that after making > $100 profit you increase your "unit" bet proportionately.
ie. if you were originally betting in 50c units(ie.1x5=$3.00), then after every $100 profit you increase your units to $1....etc
This is the secret of system/investment plan betting - you are increasing your wagers from accumulated profits, not recklessly chasing losses.
Give this approach some thought and all going well it should prove profitable in the long-run.

Cheers.