If you can afford, buy ES tick data for the June contract(this contract is summer months and cause lack of volume much harder to make profits generally- for past 10 years and even better all the contract months, ES is by far one of the hardest instruments to trade but had very good volume. Try to amass like 3,000 min sample sizes, anything under this you don't have enough sample to study.Don't cheap out by getting one minute data as most software's don't have any idea if you got in first then stopped out or reached target on same bar. Also, you will want to learn how to read the DOM eventually as reverting back to mean is often going for smaller but more consistent profits, but very often risk much larger. Other markets are can be easier to trade like NQ, Bund, Eurodollar spreads because of either run and gun-quick sustained moves- or much slower moves but they trend, although very slow Eurodollars it is heaviest traded contract and contract months goes out ten years.
I don't know about "safety", NOTHING is safe and even though to can have decades of experience, you have to always trade knowing if the markets stopped and you are long 50 contracts, and exchanges don't open for a week like 9-11, when they resume you are out $5,000 each contract, you have the funds to pay and recover, just cause the margins are so low, be prepared for the worse.
You will generally find in the beginning that nothing works, but trading is a puzzle based on experience, not so much of what you don't know about the markets as it is what you do know can do yourself in, HAVE to keep an open mind to everything. The smaller the targets, the more perfect your entries have to be, whereas going for homerun profits-entries don't have to be tight. Smaller profits you get your winning % have to be extremely high like 90% or higher cause usually risking more than making, larger profit trading winning % are lower cause trades don't usually end in minutes and many false moves. More the number of trades, greater amount of commissions spent, you be surprised to hear but often small funded traders have to do 100-150% of their accounts to pay for commissions each year, $4 bucks a roundturn adds up, when you might be making 2-3 ticks on average each trade and that is when you are good trader.
I think the easier way to profit is spread trading, once learned you are set for life, it is also difficult to learn, if it wasn't, everyone would be doing it. Many markets are seasonable like crops and animals.
Good luck, I don't know anyone who in first 3-7 years was profitable doing reversion to the mean type systems, you really have to perfect on entries and exits for smaller profit systems, automation is fine but you have to be talented trader first to know what to program. Always remember trend is an idea of the recent past of people who trade heavier who are willing to buy at one or more ticks worse, but there almost always periods of counter moves (dips) you can get in for reversion to the trend.
LOL, what performs best for me in back testing is staying in commodity markets for on to five years duration, when systems give a signal a reversal is due I hedge open profits and dance credit spreads around the position. Fees and expenses add up doing intraday trading, more you do plus volume really adds up and profit per trade goes down, longer you can stay in trades your profit per trade goes up. There is a difference of making 100% return in some stock in 2 years and intraday trader having to make 400% to make same monies cause of all the commissions and fees. Unlike the American way, more is not always better. Everyone seems to forget losses of income of outside jobs and bennies, the years it takes for you to become good in trading, you are losing out if you don't have that 9-5 job, whereas longer term trading you have income coming in, not stuck in a cave working years at becoming good if you go this route.
Happy New Year all.