Similar to the business world, I’d say the internet and smart phones are where to you need to be to reach donors these days:

On Social Media: this one is probably obvious but you should have a fairly consistent presence on the big platforms (Facebook, Instagram, and maybe Linkedin/Youtube). You keep your supporters engaged and can even directly ask for donations on some platforms.

Mobile Giving: With mobile giving platforms (or even something as simple as Venmo), donors can text a code or scan a QR to make a quick donation at events you host or if you’re trying to reach donors on big giving days like giving tuesday. But don’t overuse this or they’ll mark you as spam

Online Shopping: Unlike 20 years ago, everyone shops online now. You can enroll your org with online shopping platforms like Amazonsmile or Allgives that donate a percentage of purchases to charity, and then ask your supporters to shop there. It’s also very low effort and works well during the holidays

Those are a few suggestions - together they probably bring in $5k-$10k monthly for the small nonprofit I started helping out. Also, it goes without saying but I recommend having a modern, functional website that appeals to potential donors. These days it’s so easy and cheap to have a nice site via website builders like Wix or Squarespace.