It's good to share good ideas--and this is one that came across my way years ago that's worth passing on.
On the floor of the broom closet near the kitchen is our card box. It's small enough to pick up and move with ease; large enough to hold cards for various occasions. And it's simple. There are dividers labeled (by hand) for All Occasion, Baby, Birthday, Get Well, Sympathy, Thank You, etc. As opportunities come up, I have cards on hand that are easy to write in, address and pop in the mail that day.
If you are a pastor's or deacon's wife, Bible study leader, or simply someone who cares about others and wants to celebrate and share in others' lives, this is a fabulous investment that's easy to use and maintain.
"Bless those who persecute you; bless and do not curse. Rejoice with those who rejoice, and weep with those who weep. Be of the same mind toward one another. Do not set your mind on high things, but associate with the humble. Do not be wise in your own opinion." (Romans 12:14-16)
"Let us hold fast the confession of our hope without wavering, for He who promised is faithful. And let us consider one another in order to stir up love and good works, not forsaking the assembling of ourselves together, as is the manner of some, but exhorting one another, and so much the more as you see the Day approaching." (Hebrews 10:23-25)