The main strategy is that you have to play to win. You don't play, guranteed you will not win.
Second strategy is that if you play EVERY possible combination of possible numbers, it is guarenteed that you WILL win. The down side of this strategy is that there are more possible combinations than there are dollars in the jackpot.
The third strategy is that the odds against winning are so great, that buying more than one ticket does not improve the odds by any significant amount.
The fourth, (and arguably the most important) strategy is that the methods used to draw the offical lotto numbers are, by design, meant to keep the selection as random as is humanly possible, so that there IS NO real strategy in selectiong winning tickets. The administrators of the varioius lotto games take extreme measures to assure this is so.
For example, the balls for the lotto machines are carfully weighed to assure all are as closely matched as possible. There are multiple sets of these balls that are regularly rotated so that there can be no pattern of regularly selected numbers. The balls and the machines are kept under lock and key. The personell are carefully screened.
There are many more protections. Some of which are probably not known to the public.
The numbers are random. Winners are random. If there was any winning combination known, then the same people would be winning every time, wouldn't they?