You can try to divide your money in 5 stacks, and buy in different days 1/5 portions of the amount of Ethereum and Litecoin you want.
... You're right, I think that is the best strategy to divide our money for the investment so that the investors will not missed the time element. For those investors who had enough amount for investing they are the more have chances to success because they are always think positive, But to those had a little amount they had better to wait.