I use Singh-Ray Filters constantly in my photography. From polarizers to solid ND filters to graduated ND filters, they are in my bag when I go out the door. My favorite filters are the LB Color Combo polarizer, a 10 stop Mor-Slo ND filter and a 2 stop hard edge graduated ND (100x150mm size). Check out these articles I have written for Singh-Ray on using their filters:
https://singh-ray.com/author/tbol/
The sale runs from April 1-12. Now is a good time to get that filter you were thinking about…