I think it depends on the area - I've seen it happen twice in broad daylight on Clerkenwell Road near Farringdon station over the last couple of years and it's happened to a friend of mine near Waterloo.
I'm the co-founder of a web-focused consultancy which works with larger, "enterprise" type businesses to fund work with much smaller companies, usually pre-seed startups. We hire more experienced engineers to work on the ground with the larger clients and we actively hire more junior engineers to work alongside a small number of experienced people on the startup projects. We find this offers solid on-the-job training for the juniors as they rapidly get exposure to a wide range of skills and technologies without necessarily being hampered by legacy codebases, massively complex change management and deployment processes and office politics.
We network at meetups, conferences and other events, so through word of mouth mainly. The active engineering community in London is fantastic at helping to spread opportunities.
A colleague and I left a large UK company and started orangejellyfish (https://orangejellyfish.com), a software consultancy with a focus on the web and JavaScript. The real push to start it came when we realised that much of what we both wanted to achieve in terms of craftsmanship, maintainable code and training in new technologies for engineering teams not yet exposed to them, was not going to be possible. We knew that many businesses do have a desire to improve those aspects of their engineering teams, and when we came to an agreement with a company that would become our first major client we decided that the time was right to both commit ourselves full-time.
We've doubled in size from our initial 2 in the last couple of months and with many more prospects on the horizon we're hoping to add a few more to that over the course of the next year!
I chose a lab-grown diamond to have set in my fiancée's engagement ring. It looks stunning, is significantly larger than I would have been able to afford if sticking to "natural" stones, and nobody can tell the difference. It's certified by IGI, which most people will tell you is not a good thing (you would generally look for GIA certification, and GIA refuse to certify lab-grown diamonds), but if you find a stone that is graded highly across the board by an IGI lab (colour D or E, cut Ideal or Excellent and clarity >VS1) it seems unlikely you'll be disappointed once it's set in a ring.