What I advise in this regard is to study the market carefully and never buy when the price of Bitcoin is high regardless of your DCA approach. Take the recent event for example, Bitcoin hit almost $27,500 recently, and that was when I knew fresh trouble might start, and you can see what is happening now. Nonetheless, if you are conversant with Fibonacci retracement, you would know decisively in line with the price action that the coin was stopped by the 61.8% 1D Fibo level and a bearish price action below the line pointed to a bullish failure and an activation of a bearish short-term reversal. At this point, a good investor will know what is going on and wait until there is the same condition favouring the bullish trend before buying the coin again. This is wiser than just buying and DCAing without a good reason to back it up.
This was how I was able to know how to deal rightly with my Bitcoin purchase when a similar condition happened in August when Bitcoin moved higher and barely hit above $28,000. It was the same Fibo that played out so well to guide me as 1W Fibo level actually repelled the price of the coin downwards. It's good to make plans this way so that one will not be a blind buyer, and once you buy at a reasonable price, you tend to make more money. So, it's not only about DCAing but DCAing rightly with further guidance like this.
This means that if I have bitcoin is 20k, I might DCA with 30% and when the price is between 24k-28k 20% and anything 30k-34k let's say 10% and when the price is above 37k, you can also choose to stop buying and pause for a while to see how if the price will drop. The most important thing is that you keep on accumulating. The price of bitcoin wouldn't bother you when you are well prepared on increasing your bitcoin portfolio.
An investor that has plans and has the available resource to DCA for long wouldn't worry himself over the market price of bitcoin because he has put all that into consideration, what he will be after is to look at the price to know if he will change his strategy of accumulating to his bitcoin portfolio. Also when the market dips, then one can look for a means to get a good amount of funds that was on reserve or sell part of your other investment or take profit from there to buy more bitcoin.