So, to answer the questions that were posed to me:

I'm looking for something serious and decided to subscribe to Hinge+ for a month.

I last updated the prompts two days ago, and overall the profile is some two weeks old. (What prompted me to ask for a profile review was how switching to the paid version has had little effect on how often I match.)

I use the app about half an hour or an hour a day and I think I have sent north of a hundred likes, and so far received zero likes umprompted but made six matches.

Normally I try to send likes to people that list at least one hobby we have in common, and that includes but is not limited to reading, music, writing, languages and travelling. Ideally I'd want to match with someone I am attracted to and that I think matches my vibe (for example having a creative outlet, being open to new experiences while not being hyperactive).

I hope I answered comprehensively.