+1 to Affable Geek's proposed guidelines. As a follow up to that, I would just add one major point.
Subjective and practical questions are not exempt from our guidelines about needing to focus on a specific doctrinal tradition. Likewise, answering them must be done from the same general quarter.
A simple example would be baptism. If a practical question is asked about how to handle the water in a baptismal and the practicality issues surrounding a dunking, it would be inappropriate to answer with a rejection of immersion and defense of sprinkling as a baptism method. Maybe a comment or link to another question focused on the other tradition would be ok, but straying out of the scope of the question is not acceptable for subjective or practical questions any more than it is for any others.
By the same token, asking questions that are too broad will still be a no-no. You won't be able to ask "What is the easiest way to organize all my new converts getting baptized." You must specify what tradition you are working in, what principles you are working from on the nature of baptism, etc. You must be specific so that answers can be judged according to some baseline assumptions and their merits for YOUR situation, not for their own doctrinal leanings.
As far as answer guidelines go, we should be pretty strict about not allowing answers to practical question become platforms to rant promote each OP's favorite doctrine. Answer the question within the scope of the OP's field of operation or leave it alone.