In the light of a recent discussion about the usefulness of sub-tags for the "weapons"-tag and a short discussion with Monica Cellio in the comments of my answer I would like to discuss the future of the 300 reputation "create tags"-privilege.
Currently a new user only needs 300 reputation to single-handedly create a new tag when he is asking a question. This is pretty early compared with other tag-related privileges like "create tag synonyms" and "approve tag wiki edits". Many users with only 300 reputation will probably not pay too much attention to guidelines and Meta-Discussions about this topic and will therefore quite often create tags that may for example be too specific, as was the case with me and the "bows"-tag I created as there already was a "swords"-tag.
Seeing now that there is a "Sandbox for Proposed Tag Edits" and the creation of a new tag can lead to a longer Meta-Discussion I think it would be better to replace the current 300 reputation privilege to create a tag with a "suggest new tag"-privilege. The concept of "suggest and then wait until it is peer-reviewed until you have 2.000 reputation" is already in place for normal edits on the main site (not on Meta as there is no "suggested edit"-feature for normal posts on Meta). Therefore making the creation of new tags a "suggested edit" should feel normal for most new people, but at the same time still provide an incentive to get more reputation. Especially seeing that there is, according to Monica Cellio, already a 10k Moderator tool to view the newest tags this shouldn't pose too much of a problem.
The new "create tags"-privilege could be integrated with the "approve tag wiki edits"-privilege at 5.000 reputation. This could also be done with the 2.500-reputation "create tag synonyms" privilege.
This way users have a lot more experience when they are able to single-handedly create tags and the community in form of high-rep users has a better control over the creation of new tags. Initiating Meta discussions would be easier this way as somebody has to manually approve new tags suggested by low-rep users.
What do you think?