"At the level of the individual believer, attention to the needs of the funds of the Faith parallels the principles which govern multiple loyalties. The first loyalty of a Baha'i to the whole of mankind, for the benefit of the part is best achieved through the welfare of the whole. But this widest loyalty does not eliminate the lesser loyalties of love for one's country, for the area in which one lives, or for one's family. They all constitute a network of interdependent and mutually beneficial loyalties. So it is with the individual believer's relationship to the International, Continental, National and Local Funds."
(On behalf of the Universal House of Justice, 31 October 1993)
There is a great lesson hidden here, and it's not just about fund contributions. Our loyalty to the whole of mankind should be our highest loyalty, and a corollary is that our sacrificial giving to funds should put international concerns over local concerns. This is counter-intuitive, but absolutely correct. If everyone held their highest loyalty to their tribe, city, or state, international peace would be impossible. Everyone seeks to improve their immediate surroundings, but we also have to look beyond the things in front of our faces and seek to improve the lot of the world, and by doing so we will improve our individual lives.
For those in the United States, there is now an online contribution system (https://ocs.bahai.us) that allows electronic contributions directly into regional, national, continental, and international funds, AND it allows automatic payments at the interval of your choosing (including once per Baha'i month). I highly recommend it.