A friend told me over the weekend a trick to clean baseboards.
First vacuum around them, then use:
1/4 cup of fabric softener
1 gallon of water
A microfiber rag
With this method, you can easily clean any leftover dust or grime and repel any future dust since the fabric softener naturally repels static electricity (which attracts dust).
I tried it myself and not only did my baseboards look new again, it also made my house smell like fresh laundry.