Having been involved in building budgets for some time, I have come to realize several things about the process:
The most important thing to always keep in mind as a budget is built to to realize that the task we are involved in is not a financial work.  It is a spiritual work.  The goal of the finance committee is not to build a budget per se, it is to build better stewards.  Our relationship with Christ is strengthened through generosity and good, faithful stewardship; not through balancing a budget.
That being said, the most important question to keep before us as we do our work is “Does this budget (or line item if we choose to go line-by-line) help us fulfill our mission as a church?”  The mission of First United Methodist Church is “Making disciples…changing the world.”  That statement is not just a catchy phrase we toss about haphazardly.  It is the mission of this church.  Therefore, we need to let our mission determine our budget and not the budget drive our mission.  In other words, with each item we look at, we need to determine if it helps us meet that mission.  If it does not, we cut it or delete it.  If it does, we keep it (with any adjustments needed).  
The wrong question to ask is does a particular item generate enough income to warrant keeping it in the budget.  Such questions will always limit our mission.  If we are to be fair in this process, we would have to ask that question of every item.  And, I believe in doing so, we would realize that many of the ministries we offer do not generate much, if any, income at all.  We do not offer ministries to generate income.  We offer ministries to fulfill our mission.
I have also come to realize that pledges are a poor way to estimate income and a poor way to prepare budgets because of too many variables coming into play in a given year which impact a giver’s ability to fulfill his/her/their pledge.
Let me also share with you some of my experiences about conducting a stewardship emphasis/campaign:
1). Conducting a stewardship emphasis before building a budget allows those who give the least – or nothing at all – to set the scope of a church’s ministry.  In other words, those who do not give limit what ministry we can offer.  For example: if a campaign yields $200.000 in pledges, but what is reasonably needed to do the work of the church is $300.000, those who did not pledge or give have limited the ministry if the budget is determined by what is pledged.
2). A stewardship emphasis first often assumes that the largest givers in the church will take on the greater part of the budget needs.  In other words, if the campaign yields only $200.000, but the budget is $300.000, those who pledge of give the most often feel that they must make up the difference.  This is often seen in last-ditch, last-minute efforts to fulfill the budget by asking the largest givers to give more as the end of the year approaches.
3).  Building a budget first stretches the congregation to do more than it believes it can…all it has been called to do.  A budget-first emphasis helps stretch and challenge the congregation to grow in its discipleship by trusting in God’s provision rather than solely on those who give or the amount pledged.
Again budget building is about developing good stewards, not simply about the bottom line.  That is not to say we should not be wise in building our budget…we have a fiduciary responsibility to use the funds given in wise, biblical ways.  If we can offer the ministries of the church on less, certainly we should.  But we should not let the budget determine our ministries…let the mission drive the budget.