Back in 2006, I started my own little consultancy - I focused on Ruby on Rails (I was very early in that game - to my knowledge the first in the UK to specialise in it as a tech stack), had a lot of opinions on the Web 2.0 and tech scene more broadly, and very little cash to spend on marketing or any serious sales efforts. In short, my only option really was blogging.
My company website was basically my tech blog. Whenever people googled me or my company name (I had business cards, I did a lot of free networking events too), the blog would come up. Every piece of work I got came from that blog or word of mouth. Kept me going for 4 years until it was time to go do something else.
I think having a "personal website" in the form of a portfolio you add to and just link to from your CV might help more if you're a designer.
A blog, or at least a set of articles/editorials/deeper thinking pieces, will help if you want to showcase you're not just another monkey in a seat at a future employer as a senior developer. It will pay a lot more dividends if you want to go free-lance.
In terms of finding topics to write about, well, that's simpler than a lot of people make it. Whenever you're coding a side project, reading something on HN or elsewhere or watching a dev YT or whatever, ask yourself "what do I think about this?" and make a note in a dedicated note for ideas on your phone or in a notepad you keep nearby. If you consistently do this, after a week you'll have a list of lots of things you have thoughts about. Spot a pattern or theme? Cool, go write a blog post. Or two. Or five.
A slightly more formal method for this is called a Zettelkasten. A lot of nonsense has been written about this (and as a method, it's produced some awful writing from people who didn't understand how to use it well), but I think a good primer for this is Bob Doto's "A System for Writing" - it breaks down how to capture ideas, thread them together into something to write about, and how to then produce some good writing. It's quite lightweight once you make it a small habit, and I've been reading this recently and found it a lot more helpful than other books on the method.
In terms of tone - nerdy or professional - I would suggest you need to keep it authentic. Be you. However, be you in the context of you wanting to get hired, not you in the context of being out on a Saturday night with your friends.
The tone should not be interview formal where you're trying to be the most professional you that you can ever be, but the you where you are in the office talking about the thing you're talking about to a colleague. In fact, just imagine you're talking to some of your existing colleagues: what would you say to them about this idea? Perhaps get some of them to proof read your drafts before you post. Try not to be too negative, cynical or sarcastic (not just on your blog, in life in general), and you'll find people out there thinking "hmmm, maybe I'd like to work with this person some day".
Back in 2006, I started my own little consultancy - I focused on Ruby on Rails (I was very early in that game - to my knowledge the first in the UK to specialise in it as a tech stack), had a lot of opinions on the Web 2.0 and tech scene more broadly, and very little cash to spend on marketing or any serious sales efforts. In short, my only option really was blogging.
My company website was basically my tech blog. Whenever people googled me or my company name (I had business cards, I did a lot of free networking events too), the blog would come up. Every piece of work I got came from that blog or word of mouth. Kept me going for 4 years until it was time to go do something else.
I think having a "personal website" in the form of a portfolio you add to and just link to from your CV might help more if you're a designer.
A blog, or at least a set of articles/editorials/deeper thinking pieces, will help if you want to showcase you're not just another monkey in a seat at a future employer as a senior developer. It will pay a lot more dividends if you want to go free-lance.
In terms of finding topics to write about, well, that's simpler than a lot of people make it. Whenever you're coding a side project, reading something on HN or elsewhere or watching a dev YT or whatever, ask yourself "what do I think about this?" and make a note in a dedicated note for ideas on your phone or in a notepad you keep nearby. If you consistently do this, after a week you'll have a list of lots of things you have thoughts about. Spot a pattern or theme? Cool, go write a blog post. Or two. Or five.
A slightly more formal method for this is called a Zettelkasten. A lot of nonsense has been written about this (and as a method, it's produced some awful writing from people who didn't understand how to use it well), but I think a good primer for this is Bob Doto's "A System for Writing" - it breaks down how to capture ideas, thread them together into something to write about, and how to then produce some good writing. It's quite lightweight once you make it a small habit, and I've been reading this recently and found it a lot more helpful than other books on the method.
In terms of tone - nerdy or professional - I would suggest you need to keep it authentic. Be you. However, be you in the context of you wanting to get hired, not you in the context of being out on a Saturday night with your friends.
The tone should not be interview formal where you're trying to be the most professional you that you can ever be, but the you where you are in the office talking about the thing you're talking about to a colleague. In fact, just imagine you're talking to some of your existing colleagues: what would you say to them about this idea? Perhaps get some of them to proof read your drafts before you post. Try not to be too negative, cynical or sarcastic (not just on your blog, in life in general), and you'll find people out there thinking "hmmm, maybe I'd like to work with this person some day".