My guild is a raiding guild first and foremost, but we also have quite a few interested in pets (myself included
For all vanity items that drop during raids (mounts and pets), we do the following: Raiders roll, highest roller wins. Winner may do what he/she pleases with the item. Although we don't make it mandatory that people pass, all loot is still under officer discretion.
Keep in mind that although I say "Raider", that isn't just anyone that raids. In my guild we have three raiding ranks.
- Initiate - Those that just join and are undergoing a trial period to see if they would be a good fit for the guild.
- Member - Those that passed their trial but are still fairly new. They need to perform well and maintain consistent/good attendance while at this rank. Minimum time at this rank is 2 months.
- Raider - Those that have proved themselves to be loyal guildies and perform well enough. Strict attendance requirements are required for this rank.
So essentially, we wake into account attendance and performance (although performance is highly subjective at times, so it's not as big a factor) and seniority/longevity in the guild.