If the project gets big enough you really need to have someone just dealing with the issues. It's super time consuming. I've gotten commit access and cred on several open source projects just by going through the issue log and triaging it. There's a great post I can't find on a good triage process for issues. OSS projects are much more likely to give you access to do tickets than to commit. And on github, you can tag issues to help the maintainers sort the issues.