Be precise in environment and system information. Even though you are opening 2 tickets a week, do not expect that "the support" knows that you run on AEM 6.2 SP1 on Mongo, because you mentioned it a few times. If your problem pertains to the author, always put that information in one of the first comments in the ticket.
Attach the output of the config info collector (/system/console/status-info-collector) to the ticket, as it contains a lot of information which support might ask. The more information you provide here, the faster someone can start working on your issue without asking you for more information. Of course this not work in all cases, but it should cover the standard cases.
1 Issue, 1 ticket. Nothing worse than covering 10 different aspects in 1 ticket. That can mean, that you have to run multiple tickets at the same time. That's ok.
Respond in a timely manner. No matter what, your tickets should never (repeat: never) be closed because of your non-responsiveness. If you cannot work anymore on a topic (which means that it's no longer important for you), add it to a comment and ask support to close the ticket. If you can work on it again 2 months later, raise a new ticket and reference this old one. No problem.