Like any other organization, to improve financial condition increase revenues and decrease expenses.
On the increase revenues side, for example, seek to actively attract new members.
On the decrease expense side, you'll need to critically review all expenses and see where cuts can be made.
This is a very good question. Silent auctions are one way, galas and other community events can also help fundraise. You can also consider changing how your congregation contributes to the church. You can consider allowing recurring credit card payments (they get points and you get cash) or other fundraising tools.