Certainly churches in our modern world need a more comprehensive financial program. Tithing works. The only issue I have with "tithing" is when it's taught as a doctrine that has to be observed for a "member" to be considered "in good standing" in the church. I've seen people denied ministerial office and opportunities to be board members, ushers, choir members, etc. I've also seen it preached that if one couldn't tithe that they'ved "robbed God" and it implied that they were Hell bound. That's extortion and spiritual abuse seeing that the NT church never embraced tithing nor any other requirement such as circumcision.
So... what's a church to do? I can see a church establishing "covenant partners" or "faith partners" by having members vow or "pledge" a certain percentage or amount of their income monthly. Also the church can have fund raisers and ask for additional "love offerings" as needed. When Israel is presented as an "example" where 10% was given, typically the commitments are very close to 10% across the board. One might want to consider preaching on the blessings of the pledge being akin to the "vow" ...
Psalm 50:14-15 (King James Version)
14Offer unto God thanksgiving; and pay thy vows unto the most High:
15And call upon me in the day of trouble: I will deliver thee, and thou shalt glorify me.
I was a liaison for the United Way for about a year and a half in my previous government position. If a local charity or social service organization can function on pledges and donations... why can't a church? Also... I think churches should consider their "mission" to the community they serve. Do they provide clothing closets or food pantries? Do they offer the homeless shelter or serve as a hub directing people to charities that can help? These are important factors. I've seen many churches simply function as a "church" without offering anything to the community.
I feel that if a church is "serving" the community and the congregation has caught onto the vision funds and volunteer work may increase.
Isaiah 58:10
And if thou draw out thy soul to the hungry, and satisfy the afflicted soul; then shall thy light rise in obscurity, and thy darkness be as the noon day: