Mostly, the best strategy is just to do the DCA strategy, minimizing the risk, and it doesnt need huge capital, but just make sure you have the right financial foundation already to avoid having an emergency sell, because in long-term investment you just can't sell if you have something like an emergency, you should have separate liquidity for that in order to survive the market.
In a volatile market like this, when you’re being faced with an emergency when on a long term investment, you would sometime see that taking anything out of that your investment will be you already losing from the investment because even if you sell at that price, you’ll be selling at a loss which won’t bring back the capital you used to invest initially.
Emergency funds should not be used for long term bitcoin investment because they’re a necessity that must push you to want to take from your investment if you don’t have separate funds for that. In cases like this, it is better to allow your cash flow to improve such that money for emergency and other basic necessities are sorted out before beginning the investment.