I guess an analogy to a fleece will have to do (although, I find it quite convenient that some other element will do decided on by the inquirer), since the option of consulting the ephod-wearing priest possessing the Urim and Thummim to know the will--the yes or no--of God is unavailable (but then... why not come up with an analogy to that means?).
From one standpoint, I suppose a believer may request of God that he help with the decider's decision somehow. But does he have any assurance that God will infallibly, prophetically answer him by a sign? What about the possibility that the devil will give him a lying response and false encouragement?
"To the law and to the testimony: if they speak not according to this word, it is because there is no light in them," Is.8:20. The believer is bound to the revealed will of God, and ought not seek or demand guidance or "confirmation" besides. In the story of Gideon's fleece, we have a situation where the word of the Lord had already been spoken, yet the Lord's servant did not act on that word but insisted on not one but TWO "fleece signs" by which he might prove the solidity of the Lord's intention! To my sights, this pattern is not one for emulation at all, least of all for evidence that the Lord will stand by MY plans.
If we pray God to answer by a sign, we are putting the Lord to the test. Isaiah spoke to king Ahaz, and told him to ask for a sign (Is.7:12); but the faithless king put up a show of false piety, and refused. The angry prophet, on behalf of God proceeded to promise a stupendous sign (the virgin birth) besides furnishing a proximate sign for the immediate need that would satisfy for the believers around the king.
Ahaz understood what was ordinarily the duty of faithful men: to believe the word of God, resting in it as sufficient. Our work, our decisions should be done in accordance with the revealed will and wisdom of God, and prudent seeking for assistance from providentially provided earthly sources. We must make decisions, and these will sometimes seem to wonderfully work out... or not, or be mixed with disappointment in degree. Yet, the one who has made his effort in prayer and faith should trust that God was with him, regardless of how the outcome appears.
Prv.3:5-6 "Trust in the Lord with all thine heart; and lean not unto thine own understanding. In all thy ways acknowledge him, and he shall direct thy paths."
Ps.37:4-5 "Delight thyself also in the Lord: and he shall give thee the desires of thine heart. Commit thy way unto the Lord; trust also in him; and he shall bring it to pass."
With a heart and mind full of God, he will first put a desire and a choice in your heart, and then answer that desire with a satisfying result. Consider how in the end satisfaction doesn't come from the result but from the God of results, from God who is in perfect and ultimate control of every situation, working it out for the good--yea, the best--for those who love God and attend the word of his call, Rom.8:28