IMHO best are as follows... 1). People you have worked with. You both know what you can do and have already spent time together finding where your skillsets co

IMHO best are as follows... 1). People you have worked with. You both know what you can do and have already spent time together finding where your skillsets compliment/overlap/mismatch. 2). Friends ...but if you have never worked together, try first before jumping in as good friends don't always my good partners and a bad working realtionship can ruin the friendship. 3). People in your network who share the vision. You will have already met them at events/conferences/etc. Again, try something simple together first. 4). People on your internet circles. OK maybe unrealisitic if you live across the planet from each other but it can be done.