Well the cracks gouged out,the cracks are edge of ceiling,and in corner wall,filling has been awkward,but not impossible the plaster is very unlevel,the cracks are not even 1cm,in the worst parts,i thought would it be quicker to use pollyfiller,in tube or caulk in a tube,then put scrim on once areas emulsioned so scrim can stick,but probably not,whats making filling difficult is trying to fill from two angles on the wall,and where slight gap under the ceiling,slightly touch in is there anything i can do that would make it easier,or is it a case of practice ,practice,more practice,i have tryed even using my finger like you do with caulk to get nice finish,and draging the filling blade sideways to smooth off,i am using my favorite touprett,amazing stuff.
You need to bed the scrim as a separate exercise prior to emulsioning the wall. Bed in vinyl matt, over fill, feather the edges out, sand flat and then emulsion paint your walls.
I am afraid instructions can only help explain the process, you have to put the process into action correctly.
Try a broader filling knife to make your line. Also look to build up filler in thin layers. If you apply thin layers it will dry off quickly but when you are applying further thin layers you are softening the previus layer a little bit it makes it easier to keep drawing your filling knife along with a steady hand until you have it right, or as right as it can be. You can also straighten your filling by using the edge of a (Abranet/ sanding block to forcibly sand a straight line along the ceiling line.
Another classic mistake is not applying enough filler. With your abranet sander and Toupret, you have the right kit to sand back excess filler quickly and well.
Practice makes perfect.