Lately we have had the discussions on electric Knife use for cleaning fish and especially when you have a lot of Perch to clean.
Yes there is a learning curve but you have to keep doing it and get past the butchering stuff. The more you do the better you get.
I put my electric knife away a couple of years ago after trying it twice.....that was a mistake....I will never use anything else from now on for Perch and will now try all species.
I am sure there are many different ways but here is the way I do them and you will develop what's is the best way for you.
I start by cutting the right side fillet first. Start behind the gill and slice to just below the pectoral fins on an angle. Do not cut through the back bone so light pressure. Then angle the blade towards the tail following shaving the back bone. Cutting through the rib bones. Try to use mostly the tip of the knife and aiming the tip towards centre belly.
Be careful not to cut through the backbone especially when passing the dorsal fin, hint....learning curve.
