Here are some tips I have for those who really, really like adding hacks to their board:
1. Only install hacks that many of your users request or that you feel are critical to your site. Do not install unnecessary hacks. They make your files huge, slow down your site, and can even in the end make your board less enjoyable.
2. Beware of the number of queries that a hack generates. Also, never install a hack that queries in a loop. If you have more than 30 queries on forumhome, ~30 on showthread, etc., you're host is bound to find out that you're overloading their server.
3. Beware of hack interactions. Albeit rarely, some hacks do not interact well with others.
4. Read replies in the hack thread before randomly downloading and installing hacks. They might mention bug fixes or security holes, as well as template issues.
5. Read replies the hack thread before asking a question that is already answered. Use the "Search Thread" function to find the answer in the thread.
6. Read the instructions when you install a hack and follow EVERY step. If it works for 2000 users and not you, chances are that you installed it wrong. Uninstall it and start over.
7. Hacking your board is nobody's responsibility but your own. Rather than bump your request threads and whine that nobody is helping you, break out a PHP book or your checkbook.
8. Back up before installing a hack. While you're at it, make a cron job to back up your database at least daily. Trust me, if you don't do it, it'll come back to bite you when you least expect it. If your hosts makes backups for you, do not rely on just them.