Investing on.a monthly basis is the best options, especialy if you have some extra funds each month for continuous investment. It's good to diversify investment so besides Bitcoin to choose some other coins or perhaps some type of investment that is not related to cryptocurrency
Long term definetely should have advantage compared to short term thus you will minimize the risk and maximize the profit.
those traditional ones like forex stocks real estate etc. We can save up out of our profits then re-invest it for further expansion of business then
repeat on the cycle until you do able to make it big.
this is suitable for those who have jobs and thier salary is per month but before to decide investing in cryptos , they should first pay their priorities . when all is clear and they have some funds left , that is the time they buy coins but they should also choose the right coin wisely .
there are times that cryptos are on bullish by the time your going to buy them , if that problem occur i think its better if you refrain from buying for now and re schedule your buy times based on your observation .