I have a few different blowers and cleaning kits, i have tried blowing the crap out of the sensor while holding it inverted, i have tried wiping it with a micro fibre cloth. I am thinking about finding my old vacuum kit i had for cleaning computer cases and setting it in the body for a period of time. I had it professionally cleaned on march and since then i am super careful with changing lenses, blow/brush around the mount (usually) invert the camera and avoid doing it outside when its windy etc unless i absolutely have to. And i regularly blow out the inside and mirror etc.
Random landscape with some sky in it 3 main spots here (one bordering the right of the cloud)
This sunset shows the 3 prominent spots in the top right
This is the scary accidental long exposure i took yesterday that prompted this.