camera sensor cleaning
I always clean by own camera sensor, but having the right tools makes it a lot easier. The best way to check is by using a "Loupe" , may be a bit expensive at the outset but using it over the years has save me a fortune in professional cleaning, let alone being without a camera. Also having an "Arctic Butterfly" to attract the dust off a sensor is way far better than any blower. Of course for more stubborn dust/marks then the use of swabs and extreme such on dirt cleaning fluid.
Cost wise this kit in a presentation box from a camera show 10 years ago cost me £115. Then number of times I have cleaned my cameras has more than paid for itself.
Doing it yourself you know that no "muppet" has damaged/ failed to clean properly
Arctic butterfly spins at high speed and after about 5 seconds builds up static electricity to attract dust, so just switch it off before using brush
Seeing sensor thru Loupe to check for dust/dirt