The world is experiencing a rough start to April 2025 as investors react to the latest tariff news out of the US. Overnight, the Nasdaq Composite Index (NASDAQ: .IXIC) fell by an astonishing 6%, and ASX shares are facing pain today. I think Warren Buffett has some great advice for times like this.

Warren Buffett has led Berkshire Hathaway for decades, turning it into one of the world's biggest (and best) businesses by making several excellent, well-timed investments. For example, he ensured Berkshire Hathaway invested heavily during the GFC when the market was weak.

Aussie investors may be wondering what they should do now. We don't have crystal balls to know how long this bear market will last or how deep the decline will go. However, we can look to Warren Buffett's wise words to help us.

Share price declines help share buyers

Almost 30 years ago, Warren Buffett said in one of his annual Berkshire Hathaway letters:

If you expect to be a net saver during the next five years, should you hope for a higher or lower stock market during that period?

Many investors get this one wrong. Even though they are going to be net buyers of stocks for many years to come, they are elated when stock prices rise and depressed when they fall.

Only those who will be sellers of equities in the near future should be happy at seeing stocks rise. Prospective purchasers should much prefer sinking prices.

Getting more bang for your buck

When items go on sale at the supermarket, it's seen as an appealing thing. Yet, shares seem more scary when they're cheaper. Warren Buffett pointed out in 2001 how this seems to be different for most people when share prices go down:

To refer to a personal taste of mine, I'm going to buy hamburgers the rest of my life. When hamburgers go down in price, we sing the 'Hallelujah Chorus' in the Buffett household. When hamburgers go up in price, we weep. For most people, it's the same with everything in life they will be buying — except stocks. When stocks go down and you can get more for your money, people don't like them anymore.

Foolish takeaway

It's certainly possible that share prices could drop further than today. However, I'm going to use the sell-off as a buying opportunity. Further declines would make ASX shares even more appealing to me.

I think this is a good time to find opportunities. We may have been wishing for months that ASX shares were cheaper. Well, now they are. We don't need to invest all our cash today, but I do believe it'd be a good idea to start putting money to work with how far prices have fallen.