Depends. I'm sort of lazy. And it's not just how often but how deep I go.
If I know the gun I just fired is going to be stored for an undetermined period of time, it gets a 100% treatment. If I know I might have another gun that will need cleaning in a couple of days, I'll wait until there's two or three that need it.
Often I might just do a partial job depending on the gun. If I have an extended day with an AR and I know I'm going out again the next day or the next week, I'll do the hotspots: quick 100% on the bolt carrier & chamber, w/ barrel inspection. A mini 14 or 30 with good ammo, I might not touch if I know I'm going out again with it soon.
New guns.
The thin oils on new guns can have more preservative than lubrication qualities. So in regard to new guns (or new to me), it's always a 100% inspection, cleaning and putting on good lube. If you have it apart, might as well clean and lube.
Reminds me of buying my SKS in the 90's. I went to the pickup door at Centerfire Systems in Versailles, KY. They were having a SKS sale - $79 for regulars, $99 for paratroopers. I went back in the warehouse with the guy and he said, "Pick one". They were in a crate, each one wrapped in greasy paper and peeling back the paper, the rifle was totally caked in cosmoline. There was no "picking one" heh... you just pointed to the top one and he bagged it up.
Now THAT was a mandatory "new" gun cleaning I had to do. I used almost a whole can of brake cleaner!