Crowdsourcing: any ideas for excuses to visit my neighbors?

My neighbors are lovely, but shy! I can tell they like when I visit (they always stop to chat and we just get along well). I like seeing them, too. But in all the time I’ve lived here, we haven’t really made friends and I don’t yet feel comfortable just dropping in. I usually go over when I have an excuse, like sharing cookies or returning a lawn tool I borrowed. That happens rarely (like once a month), and I’d like it to be more frequent. But making cookies takes time and energy, of which I have little right now. Is there anything else I can do that would allow for more frequent visits? I think it’s a tricky situation: we need to spend more time together to become friends, but until we’re friends, it’s difficult to hang out.