Is it better to create a blog on a specific topic? or many categories in a blog, different niches within a single blog? I have a blog with many category niches in a single blog.
if you have loads of time, resource and people then a generic topic on multitopics are great option to build content and drive traffic. on the flip side if you dont have knowhow, resources and time, then concentrate on some niche that you are best equipped or knowledgealbe. warm regards josh
Although I'm not currently sticking to this rule, you should always try to focus on one topic if you can. It's much easier to grow your audience that way!
I think it it better not to have mutiple themes, but it depends on your aim. what you want from your blog and what kind of blog you want to have. If it is a company blog, then it's better to focus on the company and products or the industry related. Or if it only your hobby, then you can talk about things you interested, not confine to one category and update status everyday. It is your decision to make it professional or amateur.