Young investor with 3 properties, how to creatively finance more?

[Jason Pierre]

I currently own 3 properties, 2 are rentals, 1 is my primary residence. I bought a condo at 18 for $150k, currently owe $135k and it just appraised at $200k. I bought my second at 21 for $150k as well, put $40k down, but just did a cash out refi this year and now owe $200k with an appraisal of $270k. I purchased my 3rd this year at 24 for $350k putting down $50k. Houses around it have been creeping up in price since I purchased in March to about $370k.

Currently I have about $10k liquid cash but that's my measly little reserve for these 3. I'd like to purchase another in the neighborhood of the $250k range but without the cash can I creatively leverage the 2 rentals to pull something like this off?