Clean Lamp Shades Without Ruining the Fabric
I once tried to clean a lampshade with a wet cloth. The fabric stretched, the glue loosened, and the whole thing sagged like a sad umbrella. My wife still brings it up. So I asked a professional house cleaner how she handles them and her method is embarrassingly simple.

Lampshades are dust magnets. They sit up high where nobody looks closely until the light is on and suddenly every speck of dust is glowing like a museum exhibit. But fabric shades are delicate the glue holding the fabric to the frame is water-soluble in most cases, and scrubbing will tear the material.
The lint roller method
For weekly maintenance, a lint roller is your best friend. Run it over the entire shade, inside and out. It grabs dust, pet hair, and the fine particles that make the shade look dull. Takes thirty seconds per shade. I keep a spare lint roller in the cleaning caddy just for this.
For pleated or textured shades, a soft paintbrush works better than a lint roller. The bristles get into the folds and flick the dust out instead of pressing it deeper. A cheap two-inch brush from the hardware store does the job. Work top to bottom so gravity helps.
Deep cleaning without disaster
If the shade has actual stains or years of accumulated grime, you need moisture but minimal moisture. A dry microfiber cloth lightly dampened with a mix of warm water and a drop of dish soap is the safest approach. Wring the cloth until it is barely damp if you can squeeze water out of it, it is too wet.
Test on a small section of the back seam first. If the fabric darkens or the glue lets go, stop immediately and accept that some shades are dry-clean only. Silk shades in particular should never touch water fingerprints will stain permanently so stick to the lint roller for those.
White shades that turned yellow
This one surprised me. Yellowing on white fabric shades is usually nicotine or cooking oil residue, not age. A paste of baking soda and water dabbed gently onto yellowed areas (test first!) can lift some of it. Apply with a soft toothbrush, let it sit five minutes, then vacuum off with the brush attachment. Do not rub.
If the shade is beyond saving, replacement shades are surprisingly affordable and take two minutes to swap. I replaced a yellowed bedside shade for twelve dollars and the room looked like it got a fresh coat of paint.
I now clean every lampshade in the house on the first Saturday of the month. It takes ten minutes total and the difference in the quality of light is noticeable. Brighter, cleaner, less of that dusty hot smell when bulbs have been on for a while.
Quick Summary: Use a lint roller for weekly dust, a soft paintbrush for pleats, and a barely-damp microfiber cloth for stains. Always test on the back seam first and keep silk shades away from water entirely.