Don't forget to clean what is above your head. Ceiling ligh fixtures are one of the most commonly missed items in the home (and yes, even many cleaning services forget these)
When it looks like this don't get it wet right away. Take your paintbrush (yes, a paintbrush should be a part of your natural cleaning kit) and remove the dust from all the ridges
For most of your home this should be all you need to do, but in some areas (the kitchen), you might need to remove some build-up. Spray with your glass and hard surface and with a toothbrush gently scrub the ridges and wipe with a clean dry cloth . Repeat until your fixture is dust and dirt free.
For those who do not fear breaking the glass or losing the tiny little screws, you can take them down (unscrew the lightbulb first) and run them under water to remove the dust, use your toothbrush and hot soap water to clean....rinse and let dry before replacing. Do not use the dishwasher as the heat can crack the more delicate globes.