I ran a consultancy for 8 years (sold last year), and we focused on the niche of internal business software - that is, un-sexy software used by mainly boring businesses to get their internal stuff done. I feel focusing on a niche ended up getting far more leads than when we were just a generalist "We can do anything for you!" company. We had a tailored website to focus on business automation, and wrote quite a lot of blog posts on the topic - being quite specific on what we can do and examples. It took close to a year after niching down like this, but eventually we started getting some good leads from good old google search. Keywords such as custom software, business software, business automation software etc.

Having said all that - at the end of the day my consultancy also get it's best and biggest projects via word of mouth. In the end I realised it was very stressful for a small consultancy to work with too many clients, and we we small (5 people), so eventually I decided we need to focus on going deeper with our current client base rather than looking for new clients. This was ultimately a superpower, and took us to a consistent 7 figurers per year with a tiny team and a few key clients.

I sold my agency last year and have recently started writing some insights on my blog https://devtoagency.com - you guys may be a bit past this (as my target reader is a full-stack dev wanting to start a custom software agency), but you may find something insightful - I actually found it really hard to find good information on the internet about software agencies/consultancies, which is why I want to try and capture my thoughts.