How to structure a co-venture

[Zander Kempf]

I have several rental properties now and having been sharing what I have been doing with my friends and colleagues. Several of them have expressed interest in investing with me but I am not sure the best way to structure a co-venture. Better yet, I would like to take money from a couple of them, manage the purchase and deal with owning the property (tax, insurance, PM etc.) without putting in any capital and just taking an equity share at closing. 

The only way I can think to structure this would be an LLC for each property (since each one will have different owners). However the costs of LLC registered agents, annual filing and tax filings would eat into the cash flow significantly. Any suggestions for how to best structure a co-venture deal?