Why does it take a pro to clean a light fixture? Windex and old t shirt rags and a step ladder.
Vinegar and water, paper towels. Who can afford a pro?
Do the pro's have a degree in light fixture cleaning? Window cleaner, windshield washer fluid, 50/50 mix of vinegar and water, paper towels.
After cleaning and drying, wipe gently with a dryer sheet (the anti-static toss-ins) to help keep from attracting dust. We just built a house and several of the fixtures with large glass globes had that advice in the care instructions.
Unscrew the bolt at the bottom of the fixture. You can then remove the fixture and wash it in a sink or whatever. Much easier than trying to do it while it is on the ceiling!!!
For ceiling fans I use a pillow case. Just spray the inside with whatever dusting product you are using and slip over the fan blade and wipe. Hardly takes any time and you don't scatter dust all over. Just throw the pillow case in the washer and launder with towels.