Last week I literally set-up up all my automatic investing since we sold our previous home and made a profit, allowing us to become financially stable. I did 75% in a SP500 index and 25% in an intermediate bond market index. Every month I will put $500 split accordingly into those funds. This is after maxing out our IRAs. Not saying this is the best strategy but simple split with the mindset of keeping the money in there long-term e.g., over 10 years.
Does it suck seeing the money we just put in there drop? Yes. Though I know I am in it for the long haul, not the get quick rich approach or attempting to time the markets.