Your real audience
So there you are, scrubbing bugs in your open-source project. Replying to the people who opened the tickets. But have you ever thought about who your actual audience is when you're interacting with your user base?
Your whole audience
Just who are you talking to when you're interacting with users? When you get right down to it, it's not just that person, it's everyone watching. It's the next person who comes along and reads that ticket. It's the person way in the future who is deciding whether or not to even use your software.
Still, it is also that person in that ticket. A real person who took their valuable time and decided to do all the hard work of finding out how to contact you, compose their thoughts, and reach out to you.
Doing the hard parts
As developers, our job is to do the hard parts in order to make it easier on everyone else. This means that the person you are talking to is your developer. They're doing one of the hardest parts for you, often for free. If that doesn't deserve the highest respect and response, I don't know what does.
The respect you show to that person not only shows them that you value their time, but it sends a message to everyone else who will ever come along and read your responses later. That ticket is now a part of your project. Don't make the mistake of thinking about your work in terms of the code alone, or even just the code and documentation. The ticketing system for your OSS project is just as much a part of its ecosystem as the code, as the unit tests, as the documentation. Making them more friendly (and I would argue as a result, more thorough) is always a net positive.
When you are dealing with what can sometimes be a flood of demands for your attention, allow yourself to be human.
Maybe you're having a bad day. Maybe the ticket was one too many. It's ok. Let it sit till tomorrow; it's best to wait and respond correctly than rush in and not. Also you are totally allowed to apologize. If you're suddenly realizing that last week you didn't handle a ticket in the best way you could, go back right now and make it right. You can't change peoples' first impression but you can certainly change their lasting impression.
Take a break
You can do too much. Remember, again, it's always better to take time off than burn out. The tickets that take more time to fix but are fixed right will last way longer in your community.
There's no secret behind interacting with your audience. You're a person! And so are they. Keep that in mind during the process, and the results may surprise you.
If you're interested in understanding great open source communities, you may also want to watch this talk by Hannah Wolfe from FFConf. She is the CTO of the very popular Ghost blogging platform and has some great insights in her talk.