Everyone thinks of buying when the price is at its lowest, but it's hard to pinpoint where the low is, and I think now is one of those points. The best step for us to buy is to buy slowly. If we aim to invest in the long term I think this will not be a problem, because the price of bitcoin shows a good cycle for the long term. We have gone through several years where the bitcoin cycle is at a point where bitcoin will soon return with a bullish trend. We don't know exactly when, but I'm sure it will come soon.
You can do some analysis either technical where you will only rely on the charts or to the past movements of the coins or fundamental. See if there are negative news and you can use that as basis to wait before you buy but if there are positive news you can start buying because the price will likely rise. Everyone buys at lows because this is the rule of investing or trading not buying at high and then selling at high because that is unlikely to happen.
The thing that you will get with that strategy are mostly losses. We can also do DCA so that we are sure that we never miss any buying opportunities. Doing all in is fine if you think you don't have time for waiting and you are not regretful for whatever comes next.