What strategy does someone need besides to buy low and sell high? My opinion is that if you are not someone who can affect Bitcoin's price via directly or objectively, then I can't imagine what strategy will help you to profit. Maybe it's me who is bad in trading but from my experience, weekly or monthly candles are better indicator than hourly or daily candles. When you look at daily candles, you start to believe that you can predict the price but it's very frequent to something unexpected happen and your technical analysis gets wasted. Just trade once in a while and aim to buy low and sell high, that's how I succeed.
"how", because the logic of buy low and sell high is easy, but people don't know how to pay buy and sell high. What do I mean? Well when it goes down, how do you know it won't go down even more? Or how do you know it was done and will start to go up?
You can't know by just guess work, so you need to have a good strategy, a technical analysis information. Same for the upside as well, like when do you know it won't keep going higher? Or when you know it peaks at the top. That is the most important information because that is going to make a lot of money for a ton of calculations to see where is the bottom and where is the top and that is what we need to study for. Strategy allows you to hopefully find where those places are.
You'll never know how much the Bitcoin's price will go down because you are not a whale and you don't control the market, but there is one basic rule, if the price of the coin is lower than its all-time high, then you can buy Bitcoin. I say this because the history proves that Bitcoin always surpasses its all-time high, so when the price is lower than ATH, you are in a safe zone.
Also, when Bitcoin reachs all-time high and the bubble bursts, wait for the price to drop by at least 50-60% and buy then. You have to focus on long-term profits because short-term profits are very hard, daily trading is very hard but trading a few times a year gives you much brighter image about when to buy and sell. Also look at past years' charts, loko what happened after each halving, when was the crash, what caused it and etc.