Can you poskan for yourself? Does making decisions for yourself have the same limitations of general psak? I dealt with this issue in two parts. The first shiur is available: here, and summary below. For now, I will ignore the questions of bias, and return to that in my next summary (the shiur is available: here).
In general, when ruling on a question, there are three factors that must be taken into account (we have discussed this previously: here):
- Are you qualified?
- Are there external reasons (such as Kavod HaRav) that prevent you from answering?
- Is what you are saying considered psak?