I know I could offer a straight up % of return on his money and/or a percentage of the ownership. 

Navigating my first loan of this size was a learning experience, between planning for closing costs and deciding on the best down payment percentage.

I wanted to find an opportunity to partner with an experienced wholesaler who could finance the marketing potential in exchange for percentage split of the deals.

This can often get confused with the return on investment and cash on cash because over the period of one year, all these percentages are the same.

Every month when rent comes in i allocate a certain percentage to this account.

Spell out ownership percentages, re-investment of profits, owner draws, specific and shared duties, etc. 

Two members contributing $30,000 apiece would each receive a 50 percent stake in the company.In your example the non-cash member would need to work out percentage of ownership with the funding member.

In San Diego this policy is in place for a very large percentage of the C class and better units. 

You can structure the operating agreement to include your LLC as a member and define ownership percentage or you can do a JV agreement between your LLC and your brothers LLC with no membership or your brother can set up a new LLC to be a member of the property LLC along with your LLC. 

I have some real live examples broken down into percentage specifics.