Specific to Diaspora (abbreviation D*) is the ability to follow hashtags, like Collections in Google+. This implies good use of hashtags in posts. It's also good to put the five hashtags of your interests in your profile. Hashtags are not managed in comments, that I know of, only in posts.
Those create content in writing, music, the arts often use tags like #mywork
, for example. Others might be general areas like #movies
, etc. The D* search only can find people and hashtags. Some people use unique tags as collection names. For example, I use #maditations
for a certain kind of music I post. Another tip, you can create an empty aspect and share posts to that aspect you want to refer to later. You could also have a small circle of friends in that aspect, and share to them.