I have ~5 hobbies, ~15 main topics of interest and ~20 ways I like to be entertained, therefore i subscribe to these 40 subs. If I'm feeling bored, I'll go and check /r/popular or /r/all for other subs I might like. I may contribute to any of these subs as I get to know these communities over time. I enjoy meeting new people based on what they say and post, and I like to expand my perspectives to new fields in a serendipitous way
I subscribe, and from /r/popular I start to get the feeling of how reddit works. I start digging into the communities, I become a lurker, then a member, then a contributor, until I become a long running redditor
I join my community of interest (comics? 3d art? gaming? you name it), I post my own stuff. If I want to drive traffic to my own website or Youtube channel, I make sure that a source is always provided. If I want my name to be remembered, I will use watermarks and manage my own branding. People are encouraged to post my stuff to other communities, if this is relevant. If my area of interest is niche, or just new on reddit, I'll start a general subreddit and X-post my content to other subreddits in order to get noticed.
I'll start seeing fewer posts in my front page, unless I start "following people". If an OC gets posted to both user profile and a community, the discussion gets fragmented. People moderate the discussion on their own links, setting their own rules instead of community agreed ones. It also becomes harder for me to join the discussion if I don't feel "cool" enough to become a popular profile myself. Karma is becoming a real meaningful thing.
I'll subscribe and notice that most of the things happen in user pages. I go back to Instagram or Twitter or Tumblr or Youtube as they look fancier and I already follow a lot of people there.
I put a lot less effort in participating to a community, and I just upload my contents to all my different profiles with an automated uploader.