1 Chronicles 10:13-14(NASB) So Saul died for his trespass which he committed against the LORD, because of the word of the LORD which he did not keep; and also because he asked counsel of a medium, making inquiry of it, and did not inquire of the LORD. Therefore He killed him and turned the kingdom to David the son of Jesse.
In I Samuel Chapter 16, we learn of the anointing of David to be the next king. Saul had the job for the time being, but I must make note that in verse 13 we see "the Spirit of the Lord came mightily upon David from that day forward." (NASB) It's also important to note that in verse 14 we see "the Spirit of the Lord departed from Saul." (NASB)
David knew he had been anointed by the prophet Samuel, but he didn't force his turn. He waited patiently, did his job(s), and maintained his heart for God. God's plan is always perfect, and He knows the perfect time to bring about a change. It wasn't that David couldn't have been king at the time of his anointing; it's that God had a plan to handle Saul's departure before David's appointment. Just because the Spirit of the Lord has come mightily upon you, and the anointing is fresh and strong with you, doesn't mean that your season has arrived.
Allow God to create the circumstances of your season. Don't force your turn; prepare while you're waiting. Seek God's counsel, read His Word, be after His heart, and TRUST HIS PLAN. You can't set it up better than He can anyway. He sees the end before you ever see the beginning. He knows what steps you need to take to walk into your season with every blessing He has promised you. Enjoy where you are on your journey, and understand that God knows the plans He has for you.