Between the mixed messages on U.S.-China trade and concerns about an economic slowdown, day-to-day stock-picking is becoming very challenging for the average investor, CNBC's Jim Cramer acknowledged on Tuesday.

"We've got to call a spade a spade. This market isn't just volatile, it's treacherous," he said after yet another turbulent trading session on Wall Street. "I don't want the treachery, which is not going to go away, to get to you. Use it to your advantage."

The best way for investors to take advantage of the swings is to ignore them altogether, said Cramer, host of "Mad Money." Instead, he suggested focusing on long-term themes "that hold up through this madness" because they aren't tied to China or the welfare of the broader economy.

One such theme is the rise of the cloud, Cramer said. His favorite stocks in the group, which he has dubbed the "cloud kings," include Salesforce.com, Splunk, VMware and Workday, all of which tend to fall in volatile trading sessions.

Parallel to the rise of the cloud is the need for better cybersecurity, as companies increasingly choose to operate and store their data in the digital realm. For that, Cramer recommended the stock of Palo Alto Networks, also owned by his charitable trust.

Another space investors might want to consider buying into is health care, particularly managed health-care providers like UnitedHealth Group and Centene, and large drugmakers like Merck and Johnson & Johnson, Cramer said. The idea? People will need medicine and treatment no matter where the stock market or the economy are.

"Now that the market's come down so much, I'm also looking for stocks with ridiculously high dividend yields and strong balance sheets," the "Mad Money" host said. "You might consider ... AT&T, which sports a 6.7 percent yield here and has enough cash flow to even raise the dividend if they feel like it."

Investors could also use a strategy Cramer called "wide scales" to buy high-quality stocks as they trade lower, said the longtime stock-picker.

"If you wanted to buy, say, some Microsoft, which has a terrific cloud business, you wait for a swoon and you put orders in for — let's say you want to buy 100 shares — 25 shares when the stock goes down from $108 to $106," he explained. "Then you buy 25 at $104, and then you buy 50 at $100. That way you don't feel like a moron if you buy something and it keeps going lower."

"If you do it my way, what's the worst-case scenario? The stock goes higher and you've got a profitable position that's smaller than you might like," Cramer added.

The key is to stay away from sectors that are even "remotely connected to the Chinese economy" or "hostage to the business cycle," he said. Unfortunately, those pressures affect whole swaths of the market, including the industrial sector, the oil patch and the bank stocks.

That's also why Cramer suggested steering clear of exchange-traded funds, or ETFs, many of which include both stocks that have nothing to do with China and stocks with a sizable amount of China exposure.

"Better to pick individual stocks and forego the 'group' risk you're exposing yourself to with most of these ETFs," he said. "There's nothing wrong with owning an index fund if you don't have the time to research individual stocks, but beyond that, you'll be better off trying to pick individual winners in addition to indices."

All in all, investors should use this intraday confusion to buy "high-quality, secular-growth stocks into weakness," the "Mad Money" host said. "And if that's too tough for you, there's nothing wrong with sitting on the sidelines and waiting for a better time to get into an index fund."