No pain no gain !
Even if you gamble with care, you still able to loss or just make small profit.
I'm suggest if you want to gamble just make sure that you're prepare for lossing rather than winning !
There is no way for betting safe in a gamble,if you wins you can make more money or it will be your fatal bro.
But there are some ways available for not losing your all investment.Make sure you have time and money limit on gambling to reduce yiur losses in gambling.
I think there is a one way that is, pick only the low odds to bet then your winning chances will be high.