Ideas for investing rental Cashflow.

Question for buy and hold investors..After putting money aside for reserves, what do you do with excess cash from your rentals?

1. Use it as downpayment to acquire more rentals?

2. Use it to payoff mortgage on existing rentals?

3. Use cash for Private money lending?

4. Push money into Other asset classes like stocks or Index Universal/Whole life policies?

5. Just let money sit in the bank for liquidity?

Would love to connect and learn from other smart investors on how you manage money for generating returns on idle cash from rentals.