> There is no online payment method I've seen that seems easier to me than just writing a check.

How I paid bills in Thailand:

    1. Bill comes in the mail, with a QR code. Bill says I owe 413 ฿ for power.
    2. I scan the QR code with my phone.
    3. Message comes up from my bank saying, "You want to pay 413 ฿ for your power?"
    4. I tap yes. Bill is paid.

Apart from autopay (mentioned by someone else) it doesn't get simpler than that.