Have help a couple of bros here to unstuck their filters with my filter wrenches. So, for people who don't have the filter wrench, you can try this DIY method next time you have a stuck filter.
 pipe clamp
 wide rubber band
Put the rubber band around the filter and clamp the pipe clamp onto the stuck filter. It will give the clamp some friction and also acts as protection to your filter.
If you have two stuck filters, you might want to use two pipe clamps and try to turn them in opposite direction.
If your filter is stuck onto the lens, you will only need one pipe clamp and try to turn it anti-clockwise.
The best way to easily unstuck the filter is to apply pressure evenly to all sides of the filter and this DIY will work like a filter wrench.