Looking to do a bunch over the next few months and want some input on best way to protect ourselves and those who partner with us.Should we set up new LLC's, partnership agreements, separate accounts or joint account for property, etc???

@Ted Meltzer @Robin Pritts @Michelle Williams @Dhru Das @Albert W.We emphasized our group using no money down techniques to get funding, as our members utilize these strategies we joint venture with new members and get into projects.  

Has anyone created a lease that made all parties jointly responsible, but allowed one to stay for, say, 6 months, and after the 6 months, the tenants staying for 12 months become the only responsible parties? 

Are they jointly and severally responsible for the lease? 

Thanks @Wesley Williams for the intro@Jonathan Smith there's a lot you can do with just a little marketing.You could call the basement an "office" or a "den" and that's something you could market for higher rent.Also, I've written in detail about an "Inn Keeper" profit center where the landlord joint ventures with the tenant to host Airbnb/VRBO guests. 

my partner and i are looking to perchase our first joint venture we are trying to find a duplex under market value.

You might want to learn advance creative negotiation methods.I don't care where you go in the US, there are deals to be made if you know how to negotiate them.Maybe some ideas on creative methods will help you find what you are looking for.Try, Hybrid offers, delayed settlement, principal mortgages, vertical break ups, take backs, study periods, subject to public auctions, friendly joint ventures.Control and Roll is a great way to sell properties you don't own and to make fantastic profits.Charles

@Brent Spahnwelcome, Come joint our local landlord meetup. here is the link to our schedule you will certainly find local like minded people there.

I would not do individual leases but one joint lease with everyones name on it.

A partner or a Joint Venture is a good idea.