It is a smart decision, but still it's better to build something solid before you start consulting: an online presence, a blog, a podcast, network of people who

It is a smart decision, but still it's better to build something solid before you start consulting: an online presence, a blog, a podcast, network of people who know you, etc. So that your former employer is not your only source on consulting gigs. But even then, most companies would refuse, because it means they have to contact their legal department to draft a contract, and change their workflow to accomodate for you, an external entity. I've seen people transition from employees to consultants for one company, it was very smooth though. It's just that some companies would have a kneejerk reaction of "errr, dude, listen, whatever, man, just if you're leaving, then you're leaving, if not, then not, this consulting stuff, I don't think anybody would approve of, so no, either you stay as you are, or leave, sorry." Because they don't think it's important, they don't value you, and don't really care, so by becoming a consultant you're presenting a problem and additional work for them, they would rather avoid it, especially if avoiding it is the easiest thing to do - nothing. HR will find somebody to replace you. Or it may work out how you described, especially if you sell it to them with charisma and good vibes.