Request for sources: Assuming one does not have semicha, (ordination) but is learned: Can one decide the Halacha for him\herself (after analyzing the issue and investigating the sources), or is one required to ask a Rabbi (or consult a halacha l'maaseh sefer)?
Examples:
- If one is unsure of the beracha to make on a food, and investigates and determines it is a fruit, can s\he decide that the proper beracha is העץ? (I'm assuming one is allowed to figure it out by looking it up in a "brachot book." But that isn't "deciding a Halacha.")
- If one mixes meat with his\her dairy dishes, can s\he decide for him\herself what the proper Halachic course of action is?
Related: Am I allowed to answer my friend's Halacha question? Note: None of the answers there provide adequate sources.