Decision-making can be a daunting task for anyone, but Christians have the unique advantage of making decisions that are informed by God's Word. To do so, there are at least three factors to consider.
First, you must obey the moral will of God as it is revealed in Scripture. If Scripture prohibits the action in question, your decision is easy: don't do it.
Likewise, if one of the options in your choice causes you to neglect something God specifically commands you to do, you are required to make the choice that will allow you to fulfill your biblical obligation. For example, if God requires you to be an active part of a local church -- Hebrews 10:25 indicates that He does -- any decision that prohibits you from that is against God's revealed will. In order to uphold God's moral will in your decision making, ask yourself, "What does God's Word say about it?" If it says anything, obey that (1 John 5:3). If it says nothing, you have freedom and do not need to fear missing God's will or sinning against Him (Romans 14:2-6, 22).
Second, good decision-making requires that you exercise biblical wisdom. Such wisdom comes from a diligent study of God's Word, coupled with God's generous provision. James encourages those who lack wisdom to "ask of God, who gives to all men generously and without reproach, and it will be given to him" (James 1:5). To make wise decisions, you need to gather necessary information, consider all the options carefully, seek godly counsel, and then choose the option that is most sensible (Proverbs 2:1-11).
Finally, you need to consider your own desire. If the Bible is silent about your decision, and if one choice is not clearly wiser than the other, then do what you want. You have the freedom to do so, and God sovereignly works out His plan through your desires (Psalm 37:4; Philippians 2:13).
The above process presupposes that you are submitted to Christ and filled with the Spirit. Otherwise you won't be able to make biblical decisions, as sin blinds your ability to understand and apply God's Word to your life. However, if you do have a vital relationship with the Lord Jesus Christ and are walking in the Spirit -- as opposed to the flesh -- you are free to make decisions so long as they don't violate God's revealed (moral) will. You shouldn't be concerned that your decisions will somehow derail God's sovereign will for you life, because He routinely works through your decisions to accomplish what He purposes.
For a more thorough explanation of this crucial topic, consider these resources: